2nd cycle after miscarriage! No OPK yet!

Claire • Mom of a 🌈 👶
I'm usually a well oiled machine and I'm getting a BFN every time I take an OPK! I've been feeling awful and going in to the doc again on Friday. AF showed up on schedule earlier this month. 
How long did your 2nd positive show up on OPK after a miscarriage. 
I'm seriously worried!! 😳😢😳
TIA!!