I know that blue dye HPTs are known for false positives, but does anyone know about blue dye OPKs?
The first month I was taking OPKs I used pink dye FR OPKs and didn't get a positive.
Then for the next five months I used Clear Blue Easy OPKs and always had a line (mostly faint) and each month I got a positive.
This month I'm back to FR OPKs, I'm on CD20 and I still haven't had a positive (and have barely had lines).
I know it's a stupid question, but do you get evap lines on OPKs???