What is an ovulation test?
An ovulation test works by detecting the surge in the hormone luteinizing hormone (LH) which peaks just before ovulation. They work in a similar way to pregnancy tests but instead of peeing on the test you pee into a container and dip the stick into it. You need to hold it in the urine for a specific amount of time (see instructions as the time for each brand will vary). Then you wait for 5 to 10 minutes for the test results to develop.
Do ovulation tests work?
Yes they really do and without using OPKs I would of never conceived my son. Some women are lucky enough to ovulate on the same time every cycle and I envy them so much. Trying to get pregnant when you have irregular and long cycles like mine is very difficult. This is why I have dedicated a section to ovulation tests as they can be extremely useful and save a lot of guess work. I will take you through how to use them most effectively and the most common mistakes made when using them. I will also give suggestions of the best ones to buy and answer the common question of whether OPKs can be used as pregnancy tests. I will also give you a quick review of the Clearblue ovulation monitor which I tried and tested.
When is the best time to take an ovulation test?
The hormone you are testing for when using ovulation tests or OPKs is luitinizing hormone (LH) which is the hormone that peaks just before ovulation. The peak in LH may only last a short amount of time so it is important that we catch that surge and get our positive test. When I first started using OPKs I would test in the morning which is what the instructions said to do. My cycle were quite long and I became a bit obsessed about missing my LH surge so I started peeing on them morning and evening as well. Every single cycle that I ovulated the OPKs would be negative in the morning and positive in the evening the day before I ovulated. It seemed that for me they worked better in the evening. I would not drink anything from around 4pm and hold my urine for 2-3 hours so it was nice and concentrated and then do the test. I caught my surge every cycle. I have friends who told me that OPKs never worked for them so I suggested peeing on them in the evening and it seemed to work for them too. It turns out that our levels of LH increase throughout the day from morning to evening so this method makes sense.
How long after the LH surge does ovulation occur?
This depends on the individual but it is usually 12 to 24 hours after it has reached the threshold level.
How long do ovulation tests stay positive?
I found that my ovulation tests were positive for up to 24 hours but the surge can last a varying degree of time. It can last just a few hours and for those women that this happens to, OPKs may not work for them if the test at the wrong time.
When does ovulation occur after a positive OPK?
If you get a positive OPK i.e. the test line is as dark or darker than the control line, then it is a very good indication that you are about to release your egg within the next 12 to 24hrs.
How to read an ovulation test?
It was always very confusing to me when using OPKS that I would get a faint line on a ovulation test throughout the follicular phase before I ovulated. I would always get excited when I would see a second test line appear, especially when it was quite dark and I would think I was going to ovulate the next day but didn’t. The next day the tests would be negative again and I knew from my temperature chart that I hadn’t ovulated so it was very frustrating. If I wasn’t taking my temperature every day and monitoring my other fertile signs I would of believed I had ovulated when I hadn’t and probably missed my fertile window. After a bit of reading I found that we actually have LH in our systems all the time at low levels but they can fluctuate throughout your cycle. So unlike pregnancy tests you will have a second line on your test almost every time you take one. Below is an example of a cheap OPK taken on day 10 of my cycles. As you can see there is a second line but it is faint compared to the control line. I didn’t ovulate for another 10 days or so.
Are ovulation tests accurate?
Yes they are. The key is for the second line or line furthest from the green part (test line) to be as dark as or ideally darker than the control line on the ovulation test and for all your other fertile signs to be in place i.e. signs that you are ovulating. Below is an example of a positive cheap ovulation test which I took a few months back. I ovulated the next day and got my temperature rise the day after.
Is there such a thing as a false positive ovulation test?
The answer to this depends on the individual and the type of ovulation test they are using. If you are solely using the cheap test strips then it is really down to the individuals’ interpretation on whether the test line is as dark or darker than the control line. If you see a dark line and you have your other fertile signs and you know you ovulate regularly then it is more than likely that a dark test line means you have a surge in LH and will ovulate soon after. With the digital tests you will see either an empty circle or smiley face so you don’t need to decide for yourself. Of course, just because you see a positive ovulation test does not mean you will definitely ovulate afterwards. This can happen with anovulatory cycles where the LH surge may occur (and you get a positive OPK) but it doesn’t reach the threshold level needed to stimulate the release of the egg so you do not ovulate. Instead, you get your period a few days later (more on this in the fertility issues section). This is why it is very important if you do not know that you are definitely ovulating to start charting your temperatures. If you get a positive test but no sustained rise in your body temperature then it was a false positive. Below are two different brands of ovulation tests. As you can see the one on the top doesn’t look positive (the test line is not as dark or darker than the control line) but the one on the bottom is. I double checked with a Clearblue digital test and got a smiley face and my temperature rose two days after so I know I ovulated.
What is the best ovulation predictor kit?
I have tried several different brands of ovulation tests but I found that some were 5 times more expensive than others and worked in the same way. I started out using the Clearblue ovulation tests and although they work great and I found them to be very reliable you can only get 10 for around £16.
Due to my long cycles and because I was a pee on a stick addict and I wanted to test every day from day 12 in my cycle, I soon realised after several months that the costs were adding up. I would often ovulate as late as cycle day 35 so it just wasn’t feasible for me to use them daily. I then tried the cheap ‘one step ovulation test strips’ you can get off amazon and although they do work they were sometimes difficult to interpret.
I would spend so long trying to decide if the line was as dark or darker than the control line and found it so much easier to just see a smiley face like on the Clearblue digital ovulation tests. Despite this annoyance they did work and you can buy as many as 100 for £16 so much cheaper and I could use one everyday without wasting tons of money. What I ended up doing is using the cheap ovulation tests each evening when my other fertile signs were showing (particularly a change in my discharge – see section on ‘how to make the most of your fertile window’) and then if I got a positive test I would then double check with the Clearblue ovulation tests. I found it useful to double check as sometimes I would get a positive on the cheap sticks but a negative on the Clearblue sticks and I would not ovulate the next day. If I just relied on the cheap ovulation test strips, I could have missed ovulation. Every time I got a positive on both types of tests however I ovulated the next day. Clearblue are actually recruiting women to do a clinical trial on their new range of ovulation sticks. You get free ovulation tests and £100 worth of love to shop vouchers. Check the offer out here.
This is asked a lot on trying to conceive forums. Lots of ladies get the fertile egg white cervical mucus each cycle but OPKs don’t seem to work for them. This is quite common and the first thing I would say is to change the brand of ovulation test. The picture below is posted here again to show you why.
The top test I would say is negative but the bottom one is positive. Tested with the same urine, the different brands gives differing results. In addition to this, some women only get a surge in LH for a short time (6-12 hours) before it disappeared from their system. If you are consistently getting negative OPKs each cycle then it is worth testing twice a day as you may be missing it. Once around midday and once in the evening from 7pm on wards will double your chances of catching the surge. If you still are not getting a positive OPK then I suggest you start charting your ovulation if you are not already, to confirm you are actually ovulating each cycle. The odd anovulatory cycle is quite common but if you are not ovulating on a regular basis it is time to see your GP. In the mean time, you can have a look in the Fertility Vitamins and Fertility Herbs section for natural ways to stimulate ovulation (soy Isoflavones in particular may be helpful).
Can you use an OPK as a pregnancy test?
The pregnancy hormone (HCG) and luteinising hormone that the OPKs pick up have an almost identical structure. OPKs cannot distinguish between the two hormones so can in theory pick up the pregnancy hormone in your pee. So can ovulation tests detect pregnancy? This is a question that is often asked on trying to conceive forums as women have missed their period and they haven’t’t got a pregnancy test at hand, so pee on an OPK. They get a second line on the ovulation test and then wonder whether they could be pregnant. I tried this when I was pregnant with my daughter and I can confirm that they do pick up the pregnancy hormone however they shouldn’t be relied upon. I got pregnant with my daughter when living in Gran Canaria, Spain and you can only buy pregnancy tests in pharmacies there. You can’t buy them in supermarkets or in your local Boots store. They were 10 euros for 2 so I couldn’t afford to buy a lot of them even though I wanted to test every day for the first few weeks of my pregnancy. I was super paranoid about having a miscarriage (having had two in the past). I used up all my pregnancy tests so began peeing on the cheap OPKs I had lying around. I can confirm they got darker and darker each day and soon reached as dark as they could possibly get when I was around 6-7 weeks pregnant (see below).
Although I can confirm they do pick up the pregnancy hormone I would say they are not a reliable indicator that you are pregnant before you have missed your period or within the first few weeks or so after you have missed your period. This is because (as stated above) you always have LH in your system so you will always see a second line on the test so you will always have doubt in your mind. Pregnancy tests are more reliable as you will only see a second line if you have the pregnancy hormone as they can distinguish between the two hormones. OPKs can work well as pregnancy tests if you are further along but not at the beginning.
The Clearblue fertility monitor review
I bought a Clearblue fertility monitor when I first started trying to conceive and I think if you ovulate regularly but not on the same day each cycle then they would be a great buy. This monitor didn’t really work for me as I had such long cycles at the time. I spent a lot of money buying the sticks you use with the monitor and all it would tell me day after day that I wasn’t fertile yet (which was correct). I gave it away in the end. I would definitely give it another go if I was to try and conceive again as although my cycles are still long they are shorter than they were and I know I don’t ovulate before cycle day 25.
The reviews I read online are great and a lot of women get pregnant very quickly using this monitor as they are so precise (99% of ovulation predictions are correct). Clearblue claim that their monitor improves your chances of conceiving naturally by 89% by detecting more of your fertile days than an ovulation test alone. You can also use it to detect if you are pregnant by using special sticks to use with the monitor. It detects LH as well as estrogen levels so it can tell you when you are approaching ovulation and when you are about to ovulate giving you around 4 days notice. It also has a touch screen and enables you to see summaries of your charts over the previous 6 months. If you really want to take control and find out precisely when you are fertile then this monitor is great. You can buy the Clearblue fertility monitor and ovulation sticks separately or you can buy the fertility monitor with 20 sticks included which also comes with 4 free pregnancy sticks that you can use with the monitor.