Miscarriages

I’m 18. And have had 3 miscarriages. All three were with my boyfriend if 6 years. First time was without using a condom (our fault) and we didn’t know how we were going to handle it. Second was the condom breaking and we were somewhat prepared. Third time was being on the pill for two days then having unprotected sex and deciding to keep the baby (even though that didn’t happen). So I went to my doctor and they said I was completely healthy and perfect for having children. But something is telling me otherwise.