Hun - in the beginning of pregnancy, the uterus is beginning to grow to make room for your baby - when the uterus grows you get crampy "growing pains". Don't stress!
Unless it's heavy cramping accompanied by bleeding I wouldn't worry too much, all is completely normal. I would never have suspected I was pregnant until I realised I thought AF was coming for at least ten days due to cramps.

Congratulations & Welcome to BB!