Many of us know exactly what a positive OPK looks like: the test line that’s as dark as the control line.
But… did you know that not all pee-on sticks work the same?
The case of the missing test line
If you’re looking to CONFIRM ovulation, progesterone test strips are the way to go. The test checks for the presence of metabolized progesterone particles (called PdG). If a certain threshold is reached, the test line actually DISAPPEARS!
So they do the exact opposite of OPKs, where a strong test line means that you’ll soon be ovulating. So if you still see the test line; it means your progesterone levels didn’t reach the threshold (yet).
They’re not purposely trying to confuse you by going the opposite way; it’s just that the structure of the molecule makes it impossible to create a test that works the same way as an OPK.
– OPKs can 𝐩𝐫𝐞𝐝𝐢𝐜𝐭 ovulation: the test line should be as dark or darker than the control line.
– Progesterone tests can 𝐜𝐨𝐧𝐟𝐢𝐫𝐦 you’ve ovulated. The control line should be the only line that shows up.