Hello, My Name Is Danielle Anderson. My Fiance And I

Hello, my name is Danielle Anderson. My fiance and I had sex on the first day of my ovulation cycle where id be fertile. He finished inside me (not a lot). I had all these signs of being pregnant but now I got my period. My cramps are really bad and it seems like I'm bleeding more then usual. How would I know if I was having a miscarriage?