I had my period Feb 5,2010 (Friday) and had unprotected sex on Feb 6 (Saturday). He didn't cum inside of me so he'd always pull out and I took my emergency birth control pills right after we had sex. I ended my period on Feb 9 (Tuesday), then Friday (Feb 12) I got my period again. My second period lasted for about 5 days. I usually have a regular period, meaning I get my period after every 28 days. What could this mean? Is this because of the emergency birth control I took? Or is this a sign of pregnancy?