Should I be worried??

Sooo I'm a little worried because my boyfriend and I had sex on the first day of my period and it was the first time he ever came in me...I read that there is a very low chance of pregnancy during that time and everything went as normal with my period, but I'm freaking myself out thinking that there may be a small possibility that I'm pregnant. The day we had intercourse was may 8th...I'm kinda just looking for reassurance that I shouldn't worry..