Tubal pregnancy

Hey ladies I've always been afraid that one day I would get pregnant and it would turn out to be a tubal pregnancy.... Well I'm pregnant and I'm sooooo happy about that. But I have been having some sharp cramping pains in the pelvic area. I'm about 3 weeks. Maybe 4. Anyway is that normal? The reason Ive been afraid is because several times doctors have told me since I have severe cramping during my period that it could mean I would have pregnancy issues. If pelvic pain is normal then that's great... If not how soon should I see a doctor?