Tampons & pain

Soooo I’ve been using tampons since I was in middle school and I’ve always been pleased especially since I play sports so they are more comfortable than pads BUT this time that I’ve gotten my period and put a tampon on... I’ve been getting spurs of pain just coming at random times. I feel my uterus tighten and so much pain cramp all around my bottom half of my body that I can’t even walk. My vagina hurts at the entry and it has been so painful, has this happen to anyone else??? Is this “normal” or should I just hit up my doctor ASAP? I’m 18 and have had enough period to know what a normal or at least what my period feels like.