OPK Test Run - Oh What a Difference a Day Makes

When my cycle started over in March I only vaguely thought about it being the last cycle before TTC. I had already been temping/charting for years and paying attention to EWCM, etc. but I was saving OPKs for closer to "go time". A few days after AF was done, I was researching TTC and how to prepare. One website said it was best to test your cycle with OPKs for three cycles before TTC. Oh crap! I only had one cycle to test and, because AF was already done, it seemed like it was too late to order cheapies online, so I ran out and bought some mid-price ones. They came 10 to a pack with one bonus pregnancy test. Ten would be enough, right?

Through my charting I noticed my cycle had calmed to a somewhat consistent 34 day cycle, with ovulation happening on average between CD21-23. According the the instruction pamphlet that came with the OPKs, I should start testing on CD17, and I should expect to get a second line as dark or darker than the control line on CD19 if I expected to ovulate on CD21. The test also said to use FMU to test with.

• CD 17: Tested once in the morning. A light second line but not close to the color of the control line.
• CD18: Morning test didn't work. TMI, but I don't think I held it in the stream long enough. I grabbed another test and took that to use during my lunch break at work. Another light second line.
• CD19: Two tests, one in the morning, one in the afternoon. The morning one was light and the afternoon one seemed light too, but then darkened to almost the same color as the control line a few minutes after the window of time in which you are supposed to read the test. 
• CD20-24: I continued testing, sometimes twice a day, sometimes once a day, as I was afraid of running out of tests. I even reused the CD18 test that hadn't worked originally and it actually worked the second time. During these days my second line never seemed to get dark enough within the timeframe in which the test should be read. By CD20 I ordered some cheapies and I ran out of the mid-price tests on CD24.
• CD26: Cheapies arrived! (So I missed CD25). Inconclusive but still negative.
• CD27: Total failure (see picture). I have no idea what went wrong.
• CD28: Didn't test
• CD29: Clear positive!!!

This entire time I had been getting very little fertile CM and no EWCM. Predictably, I started getting EWCM on CD25 when I didn't have a test.

I did some googling and learned that the body can gear up to ovulate, not ovulate, then later gear up again. This can give you lines that get progressively darker, then lighter, then darker again. I think that's what happened to me.

I should have taken pictures of the tests closer to when they were used. You can't tell in the photo but all of CD17-19 had second lines and the CD19PM one actually had a dark, though not quite positive, second line.

CD17-19

CD20-24

You can see that CD20 still shows a fairly dark second line, then it gets lighter until CD24 when it gets dark again. Unfortunately none of these lines were nearly this dark within the testing window.

CD26 & 27

As you can see in this one, there appears to be three lines in the upper test. I believe the first purple "line" is just where the plastic part actually ends, the middle line is the test line, and hiding among the streaking is the control line. This test was taken in the afternoon of CD26. As you can see the test for CD27 really didn't work at all.

CD29

 Finally a clear positive! At least I know the cheap tests do work. Also, according to my temp chart, I ovulated the next day which makes me wonder if I would have gotten a positive had I tested on CD28, since it's supposed to measure the surge about 48 hours prior to ovulation.

This cycle has been far longer than any I've had recently (though I've had longer in the past). I wonder if it had anything to do with nerves over trying OPKs for the first time, or stress over upcoming TTC? Maybe it was just a fluke?