False OPK? I’m confused...

Allison

I thought this was our month for sure. I got my very positive OPK on cycle day 17 and 18. A negative OPK since. I did blood work on cycle day 21 and 23 (today). My bloodwork from cycle day 21 showed a progesterone level of 5.7. I am heartbroken. What does this mean? This is our first month with medication. I take Metformin, a Prenatal, 7.5MG cycle days 3-7 and Medroxyprogesterone to start my period.

Any opinions? I have lab work again on cycle day 25.