I'm going to die.

I met up with a friend that I've known since we were born in my hometown for Thanksgiving. We hung out late on the Nov 23rd and kissed for the first time and we eventually had sex that night as well. I started my period on Nov 22nd. After the intercourse, I spotted until the 25th. We met again for Christmas and the same thing happened. I was supposed to start my period on Dec 23rd but now I'm 12 days late. The friend knows and is being super supportive. He used a condom both times. Should I be concerned?