Ovulation Kits and Period Tracking Apps

Medical training is a lifelong process.  During my residency in Obstetrics & Gynecology, we learned the essentials of management on Labor & Delivery, hospitalized patients, surgeries, and office practice.  During residency, the focus is generally on the critical elements- in other words, trying to prevent the really bad stuff from happening.  So things like management of preeclampsia and postoperative infections got top priority.

Which means that more day-to-day concerns in office practice, like common discomforts of pregnancy, were inevitably less of a priority.  So now that I’ve been in practice, I have continued to learn more about the issues that aren’t life or death problems, but are important concerns for my patients.

Ovulation predictor kits are one of those things I recently learned more about, because I finally used them myself.  I did my residency at a county hospital with low income and uninsured patients.  What I recall being told was that the kits aren’t always reliable, so having regular intercourse should result in pregnancy, and they were a waste of money for these patients.

So I brought that mentality with me after residency.  For my working class patients, it seemed like spending their hard-earned money on ovulation kits was probably unnecessary.  Plus I just didn’t know that much about them.

Then one of my colleagues, who had been at another practice for many years before coming to ours, told me that she generally tells her patients who are trying to conceive to use them.  She figures that even if one has regular periods and is timing intercourse, if ovulation isn’t occurring on the date predicted by the period tracker apps, you might be missing it.

I then talked to another colleague, who said that she doesn’t recommend them for everyone trying to conceive because some will conceive quickly on their own.  But for those who don’t conceive after a little bit, they can consider checking for a few months to get a sense of when they ovulate, because maybe they don’t follow the textbook pattern (14 days prior to the next menstrual cycle).  And then if there’s a predictable pattern, they can continue to time their intercourse.  And definitely for the patients with irregular periods, it’s helpful to know when they’re ovulating.

Before I get to the ovulation kits, I should mention that I downloaded a couple of period tracker apps.  There was a study that looked at free iPhone menstrual tracking apps for accuracy, features, and functionality:


It was a bit disheartening to learn that very few of the apps used medical professionals when designing the app.  So the accuracy of the tracking and information provided is questionable, and that means many women out there are using these free apps that aren’t necessarily reliable.  Now, this study was published in June 2016, so based on when they started the study, they used apps that were available in January 2015.  So by now there are a lot more apps that have been created.  Based on their ratings of the 20 apps they reviewed for the study, two seemed the most reliable to me: Clue and Glow.

So I downloaded both and have been using them to track my periods and predicted ovulation dates.  Both are easy enough to use.  I like Clue’s calendar view which also puts a star on the predicted ovulation date.  Glow’s benefit is that there’s more of the social media community and articles, in case you are interested in that.  Glow puts a percentage on each date, so for example it will say you have a 25% chance of pregnancy if you have intercourse on the ovulation day.

I just track my periods to predict ovulation, so I haven’t used the other features of both apps to know how good they are.  But they do have options to track a number of other things, like mood, sex drive, heaviness of menstrual flow, etc.  Both apps can be used by women trying to conceive, as well as those who just want to track their menstrual cycles.

I’ve only used the ovulation kits for two months, but it was interesting that Clue predicted the date accurately on the first month, while Glow was a little off.  The second month, both apps were off by a day (the day before) compared to the ovulation kit.  I have regular periods, but they do vary a bit from month to month.

On to the ovulation predictor kits.  The basic kits work by detecting the LH surge via urine test.  So you pee on a stick like with the home pregnancy tests, except instead of hCG, it’s looking for LH.  The LH surge occurs about 24-36 hours before ovulation, so typically once you see the positive test, you want to have intercourse the following day.

Clearblue also makes a fancier test that they call the Advanced Digital Ovulation Test.  In addition to checking for the LH surge, they also look for the rise in estrogen that occurs prior to the LH surge.  Their claim is that it identifies more fertile days.

Hormones Evolution Graph

This image is from their website, and they explain more about their product here:


I decided to compare this product to a basic LH ovulation test.  I just went on Amazon to see what was inexpensive and got decent reviews, and ended up with the Wondfo brand, though there are many other similar ones.

First, the price difference.  On Amazon, the Clearblue Advanced Digital Ovulation Test, which came with 10 strips (1-month supply), cost $28.  The Wondfo 25 strip pack cost $12.50.

The Clearblue Advanced Digital Ovulation Test

The Clearblue kit came with the digital reader and 10 strips.  They advise to start testing on day 8 of the cycle if you have a 28 day cycle, presumably because the test needs to get your baseline prior to the estrogen rise.  They have a chart of when to start testing based on your shortest cycle.

It’s easy to use- you push the test stick into the device, and dip it into your urine.  They recommend using the first morning urine.  I think it’s much easier to dip the stick in a cup rather than trying to pee on the stick.  Then after 5 minutes, it gives you a result: 1) empty circle for low fertility day, 2) flashing smiley face for high fertility day when estrogen is rising but LH peak hasn’t occurred yet, or 3) static smiley face for peak fertility day when LH peak has occurred.

Once the peak fertility day occurs, the smiley face stays lit for 48 hours and you can’t use the test again until the next cycle.  From a quick online search, I didn’t see an option to buy just the test strip refills.  Looks like you’d have to buy another kit with the reader with another 10 or 20 test strips.

The Wondfo ovulation tests

As for the Wondfo strips, they are very basic.  Each tiny strip comes in an individual packet.  You dip the strip in your urine, wait 5 minutes, and look for the lines.  Like the Clearblue, they recommend using your first morning urine.  There should always be one line that shows up which is the control line.  The second line will show up with the LH surge.  If you have a 28-day cycle, they instruct you to start testing on day 12, so that’s less strips used per month compared to the Clearblue.


So how did they fare?  Well, I did both tests for one cycle.  They both worked, and both showed the LH peak on the same day.  I did not have any technical difficulties with the Clearblue test, but there was one Wondfo strip that didn’t work.  Meaning no control line came up, so the test was invalid.  So I’d recommend that you keep your urine in the cup until you make sure you have a result before dumping it, just in case you need to do another test.

The picture above was when I saw the two lines indicating the LH surge.  It was very clear compared to the other days when only one line was visible.  I saw some women write online that they’d check morning and afternoon, so I was curious and did so with the Wondfo strips, knowing that the LH surge was coming based on the Clearblue test.  Well, I only got the two lines with the morning urine that day.  So based on my experience of using the test for a month, there doesn’t seem to be a benefit in testing more than once per day.

The Clearblue test gives you more advanced notice of when ovulation will occur.  Is that helpful and necessary?  I think that if you have regular periods, then you generally know from the app when ovulation should occur, so you can just have intercourse around that time.  If you don’t have regular periods, it might be helpful to get a little advance notice.  But that also means you’re going to need to buy more strips, which can get pricey very quickly.

So for me, based on this comparison, I think that it’s a questionable benefit to use the Clearblue Advanced Digital Test.  Given the price difference, and the fact that the Wondfo strips do in fact work, that’s the better bang for the buck.  Especially if you’re having irregular periods and or end up needing it for many months, it’s much more cost-effective.

So far no positive hCG test yet for me, but hopefully these ovulation kits will help!