I had protected sex on the March 19th and I had my period on March 13th. We used a condom on the day we had sex. The condom did not slip off or break. My expected period started on April 10th and ended on the 12th. What does this mean? Why did my period last for two days  I've been having a few headaches and nasuea and thats about it. It always come before my period.