TTC !

Had sex last night and this morning, my period starts on the 3rd, it says 1st but it always starts on the 3rd or 2nd super super fatigue like ive been off work for the past 5 days and still so freaking tired i even end up falling alseep in class and i would never fall asleep in class, and cramping and back pain but that could probably be from cracking my back to much? And mild headaches and nausea but i dont wanna overthink to much cause everymonth i would start my period. But has anyone else concieved a few days after ovulation?