Ovulation after a miscarriage

Kerrie
Hi all! I've recently had an early miscarriage at 3 weeks. I was wondering how long it generally takes for you to ovulate once the bleeding has stopped? have started doing opk's from yesterday just in case day 4 of my cycle as last cycle I ovulated of cd7. It was negative which I think is a good sign as I have read that a miscarriage can give false positive opk's afterwards making it hard to determine actual ovulation? any stories of people going through similar things would be of great help! thanks xx