Later than normal ovulation after miscarriage??

So I'm going back to a fertility clinic this month whenever I get my period. I wanted to try to get an idea of ovulation and was testing like a week ago with pink dye cheapies and clear blue digital OPKs. I never got a strong or even close to positive. Now I'm on like day 20 of my cycle and feel like I may be feeling ovulation (mild cramping) on my right side. I've tested a few times today with an opk but it's negative. Of course that tube doesn't work so it won't mean a BFP this month. I thought my ovulation day was closer to cycle day 13-16. Could the day be so off set by miscarriage? I don't know when I will get my period so it could be related to that. Any ideas? Thanks!