Period sex

I had sex yesterday but... It was really weird. We had always rushed it to get that tiny surge of pleasure and yesterday, we did a little foreplay and got him super hard. Then when he finally went in, it hurt so much when he tried going all the way in. Granted I was on my period and it was my first time doing it on my period but I didn't know whether or not I couldn't take it or whether it was just something from my period...