October 05, 2022 | by Linda Streety, RN, BSN
Can an ovulation test detect pregnancy?
Well, the short answer is….maybe. The long answer is….yes, in time you will get a positive ovulation test after a missed period if you are pregnant. The reason I say “maybe” is only because it depends on when you are using an LH test to detect pregnancy.
I stumbled upon this little “trick” after looking at hundreds of ovulation charts and noticing that on the gals who got pregnant, they had a significant increase in their luteinizing hormone (LH), the hormone that release an egg for ovulation to occur, right about the time when a period was coming due. Some women continue ovulation testing until they get their period to ensure they have located their true peak. And then it clicked with me……this makes sense!
Luteinizing hormone and the pregnancy hormone, human chorionic gonadotropin (hCG), are actually very similar from a chemical structure point of view. These two different hormones attach to the same receptors and mildly mimic each other so naturally, the hormone hCG is picked up, just like LH would be on an ovulation test. This is why some women will have a positive ovulation test several days after ovulation which may indicate an early sign of pregnancy.
How does a positive pregnancy test differ from a positive ovulation test?
Ovulation tests are not as sensitive as an early pregnancy test so they will pick up both hCG and LH as a positive test. Ovulation tests detect LH levels typically around 25mIU/mL versus 10 mIU/mL in a at home pregnancy test that looks for hCG. This means that an ovulation test likely won’t pick up a pregnancy as soon as a pregnancy test would.
An hCG pregnancy test is more sensitive so they will only be receptive to hCG, and hCG only in significant levels. This is why a woman can be pregnant and get a negative pregnancy test one day, then go one to have a light positive the next followed by a dark positive result a few days later.
When you see a positive on your ovulation test as you near your period, the only way to know if it is hCG indicating you are pregnant or a delayed LH surge is to take a pregnancy test. The LH will not show positive on a pregnancy test the way hCG will show on an ovulation test.
Should you use an ovulation test as a pregnancy test?
To put it simply, ovulation tests detect the rising of luteinizing hormone (LH) that happens right before ovulation. LH surges just before ovulation and actually tells the ovaries that it is time to release an egg. We use an ovulation test to monitor the LH levels rise and progression in hopes of predicting the day of ovulation so you are able to time intercourse to your peak fertility days to get pregnant faster.
Luteinizing hormone is essential in surging to kick start ovulation however, after ovulation it drops to low levels and will remain low through the rest of your cycle or throughout your pregnancy. LH’s job is to trigger ovulation and to help develop the corpus luteum that is left behind after ovulation, after ovulation occurs it really doesn’t have a purpose while you are pregnant.
Let me be very clear….I encourage you to use the hCG pregnancy tests instead of ovulation tests to determine if you are pregnant as they are much more sensitive and reliable when it comes to detecting hCG.
Surviving the two week wait
Truth is those in the two week wait are desperate for anything, any little piece of information that may help know what is going on with their body is calming. It doesn’t hurt anything to do an ovulation test along with a pregnancy test or in lieu of one in case you don’t have any around at the moment.
However, ovulation tests should be taken before ovulation and a few days after to confirm you levels have dropped back down while it is recommended that you test with a pregnancy test only after your missed period, roughly two weeks after ovulation.
Make no mistake, the two week wait is a beast and I’m all for having more tricks up our sleeve. But we have to keep it real as well – if you are unsure if ovulation has occurred or have not had an ovulation test reveal an LH surge then I would discourage you from using an ovulation test to check for pregnancy. If you have not clearly ovulated then a peak in LH could actually be just that, a peak in LH. There is no way to really know what the LH peak might represent, could be LH, could be hCG. So, although an ovulation test can detect pregnancy, we don’t recommend it. Always use a pregnancy test to get your final confirmation of pregnancy.
After taking all of this information in, consider ovulation tests as just another tool and we could use all the help we can get in the two week wait! Good luck and baby dust to you all!!! Xo
Linda Vignapiano Streety, BSN, RN, fondly known as "Nurse Linda" has been working in the crazy and complicated world of infertility for over 20 years; most recently she was the Director of Clinical Operations at IntegraMed Fertility. She has personally struggled with PCOS all of her life and is passionate about the world of fertility, delighting in working with all individuals/couples who are seeking to make a family. Linda currently resides in Las Vegas, Nevada is proud to have been involved in the Academy Award nominated documentary "Vegas Baby"! Schedule your 1:1 virtual consultation with Nurse Linda right through your Premom app!