ovulation test

Has Your Ovulation Test Been Wrong This Whole Time?

Ovulation tests, also known as ovulation predictor kits (OPKs) are at-home urine tests (done the same as a pregnancy test) that give insight into cyclical hormonal fluctuations and approaching ovulation. 


Ovulation tests are done to give the user insight into whether they are approaching ovulation and their fertile window. They may then do what they wish with this information depending on if they are actively avoiding or trying to achieve pregnancy. 


Avoiding would be not having penetrative sex or using barrier methods whilst in the fertile window (with the knowledge that every other form of contraception aside from abstinence, doesn’t have 100% efficacy), and trying to achieve would be having unprotected ejaculative sex. 


An OPK tests for a surge in luteinizing hormone (LH) which will typically happen within 36 hours before an egg is released with ovulation. When doing ovulation tests daily during the follicular phase, you will begin to see a line appear and become darker when the LH is surging, or you may have a digital indication of surging LH if using a digital ovulation test. 


Tests are best taken in the morning with the first passing of urine as the hormone levels will be at their most concentrated to get a more accurate reading. 


So how can OPKs go wrong? 

Some women will have chronically elevated levels of LH

This is common with PCOS as well as other circumstances, like recently coming off the pill, where LH will be relatively high even if not due to approaching ovulation. This will give false positive readings when testing for a LH surge and provide confusion around when the fertile window is occurring in the cycle which at best can lead to timing sex incorrectly when trying to conceive and unplanned pregnancy if trying to avoid it. 


Not pairing it with BBT

knowing when your ovulation is approaching is wonderful information to have about your menstrual cycle and fertility, however, this is just one part of the equation. Knowing the opening of your fertile window is one thing, but we also need to know when the window has closed for each cycle. 

We cannot assume that 36 hours after seeing a positive for a LH surge ovulation has occurred and you are no longer in your fertile window. If you are tracking your ovulation mainly for interest’s sake, it’s not a large problem, but if you are seriously avoiding pregnancy, or seriously trying to achieve pregnancy, it is crucial information to know not only when your fertile window has started, but when it has stopped. 

An increase in progesterone levels after ovulation is the sure way to confirm ovulation has occurred, however OPK’s do not test for progesterone and cannot provide this information. Pairing your OPK’s with also tracking your BBT is a wonderful way to be able to 100% confirm every cycle that you have indeed ovulated, that the positives on your OPK’s married up with what you saw on your chart and be able to confirm when you have exited your fertile window and can no longer fall pregnant for the rest of your cycle.

Ignoring cervical mucus observations

One phenomenon I have witnessed in clinical practice time and time again is women trusting the OPK over what their bodies are telling them in real-time. Too often have I heard from women trying to conceive that despite seeing cervical mucus and the opening of their fertile window, they had not begun having sex for that cycle as they had not gotten a positive on their OPK yet. 

The downside of these types of tests is that they can lead us to trust fallible external information over what our bodies are saying. Too often I have seen women not get a positive on their OPK at all, but had great cervical mucus, and a wonderful BBT chart with confirmed ovulation. 


We can’t put all our eggs in the OPK basket. Marry it up with cervical mucus observations and your BBT and you have your bases covered! 


Tracking ovulation is our jam at Femtek, we want to help you to confirm your ovulation like a pro and feel confident in understanding your cycle!

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