Had unprotected sex for the first time yesterday, and bleeding that seems like a normal period came today, 9 days early. could i be pregnant?

Possible: You certainly could be pregnant. If you don't want to get pregnant take Plan B (you can get it from the pharmacy. It's over the counter now). Or, go to a health clinic and ask for a copper iud for emergency contraception. Thats the most effective emergency contraception there is. If your regular period doesn't come in 9 days, check a preg test.