Two different OPKs:Two different Results

[21yrsurvivor]

I am trying to make sense of this. I have been using 2 different OPK brands. One is the Rite Aid brand, and the other is TrueStick brand I purchased on Amazon. The Rite Aid brand is a +OPK (got a positive yesterday, and the one today has a darker test line then yesterday). Then there's the TrueStick brand that still has me at a -OPK. I started testing at CD 11, and didn't get a +OPK till CD 17 and again today on CD 18. However TrueStick has me still negative at CD 18.

Can anyone shed some light on this for me? Has this happened to anyone else?

My CM is watery and I'm having light cramps.

Thank you fir the help

 

[pjmm]

Hi! I am thinking maybe OPKs have different sensitivities (just like HPT) ? It could be something to look into.

 

[21yrsurvivor]

I'm thinking the Rite Aid OPK is more sensitive than the true stick brand, I would get a test line but it was never the same color or darker than the control line. I will be sticking to the Rite Aid brand.