Help me please

Me and my Fiancée have had sex 2 days before ovulating and the day of ovulating and the day of ovulating I am cramping in my lower back and in my lower adomoen area like im bout to start my monthly but I'm not suppose to start until another 13 days could I be pregnant or just about to start. We have tired everything glow has told us . We r wanting and hoping to be pregnant. Are we doing something wrong ? Am I about to start or am I pregnant and this is a early sign the cramping and stuff