Wednesday, April 18, 2012

What do the lines mean on a Clearblue Digital Ovulation Test Stick?

I finally decided to switch to Clearblue Digital Ovulation Test's last month while trying to get pregnant. You can buy them anywhere and they worked great, but curiosity got the best of me and I decided to photograph each test stick this month to see if I could figure out the mystery. What do the lines mean on a Clearblue Digital Ovulation Test? Are they truly meaningless? Or can you detect your LH surge just by looking at the lines.

If you're still wondering what is an ovulation test or when to test for ovulation, you can find the directions to the tests in question here. There is only one statement concerning lines on the test stick which reads, "You can not determine your result from any lines that you see on the test stick."  That's all fine and dandy, but after months of painstakingly staring/analyzing the lines on regular opk's I felt the need to see how the lines on a digital test stick change with the LH surge and post them on the internet for people wondering the same thing.

Survey says...YES, the lines on the test stick seem to work very similar to the lines on a regular opk. they get darker close to O, and when detecting the LH surge they end up as dark as the control line.  One of the big differences seems to be that the digital reader can read a result before the line reaches it's darkest.  The digital reader gives a result within a few minutes, but it takes ten minutes or more for the lines to be their darkest.  You can see in the last pic, the test line is not yet as dark as the control. What you can't see is that test line eventually did get as dark as the control. All the other sticks, read as negatives, never had the test line get as dark even days later.

Embarrassingly, I didn't get a shot of the final and only test stick showing my LH surge although I do have the read error I got from the same sample. Apparently all that was forgotten in all the excitement of finally getting a positive.  If it's necessary for me to use opk's next month (I hope not!) I'll edit this post with a pick of that positive test stick. 

Here's the pics! I ovulated the day after my positive opk, so I've included days before positive and days before ovulation.

5 Days before positive, 6 Days before ovulation

4 Days before positive, 5 Days before O

3 Days before positive, 4 Days before O

2 Days before positive, 3 Days before O

1 Day before positive, 2 Days before O

The above pic is the day of the positive and the day before ovulation. You can see the test line is the darkest yet. It's less than five minutes after dipping. Within 15minutes after dipping the test line and the control line are both as dark as they can be. On a regular OPK that would be a very strong positive, and though this stick showed a read error. I used another stick in the same sample to get the pic below. My much wished for positive OPK.

Why didn't I put the test stick under this?!!

Hope this helped. If I go through this again next month I'll include a series of pics that also shows the sticks at their darkest after more time has past.  Happy testing!


  1. Wow just did mine and was really curious to know. Thanks a ton for the info.

  2. Wow just did mine and was really curious to know. Thanks a ton for the info.

  3. Thanks for posting this! I'm a bit late seeing as you posted a few months ago but am struggling with finding out my ovulation due to irregular cycles. I took my first clear blue ovulation test today and noticed that the second blue line is very present but not quite as dark and the other. I'm assuming this may be a good sign? :)

  4. thank you for posting this! my clear blue for the last three months hasn't been picking up my surge but some cheaper sticks have! However I have noticed a surge reading the clear blue sticks so not sure what is going on. This was really, really useful! Clear blue try and make out that only the monitor can read the sticks but the sticks can't possible work in a drastically different way to others. There is no mystique to it.

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  6. Mine just keeps popping up with the booklet symbol what does this mean

  7. Mine just keeps popping up with the booklet symbol what does this mean

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