Late Ovulation -TTC

I got a positive opk at 21 days this month. I had a MC at 5 weeks in May and another at 11 weeks in September and had a D&C. For my second MC I had a positive opk on day 18. I'm afraid that my late ovulation could be related to the MC's. Does anyone else ovulate this late and had a successful pregnancy? We've been trying to have a child for a year now. I've only been able to get positive pregnancy tests a day after my period was supposed to start.