Had unprotected sex several times after miscarriage, am now in b/c but my period has not came yet? could i be pregnant again?

Yes, it's possible: Unprotected sex always leaves the possibility of pregnancy, even early after a miscarriage. Birth control pills won't protect you until some days after they have been started, and also have a (small) rate of failure to protect from pregnancy. You should talk to your OB-GYN about the timing of pregnancy testing, especially if the miscarriage is recent. But you should be tested.