I had unprotected sex a week before my period was due. it was 3-4 days late, and now 9 days later i've started bleeding again. can they be connected?

Possibly: I would suggest that you take a home pregnancy test and if negative, please consult your GYN. I would also suggest the need for BC and protection against STD using condoms PLUS spermicidal foam, jelly, or vaginal inserts. Ultimately, unprotected intercourse will lead to pregnancy: if you are old enough to have sexual relations, you must protect yourself.