Welcome to healthcare magic!
When you had sex you were not under any protection of contraception
so you run a risk of being pregnant and the bleeding might be due to an ectopic/miscarriage/periods.
You need to get a serum Beta-hCG
level for pregnancy
test to make sure that you are not pregnant or having a trobled/risky pregnancy.
I hope you would get benefited with my advise.
Wish you a good health.