Cramping in Early Pregnancy

Marie
I have had 6 positive tests in the last 4 days. (I can't stop testing) AF was due yesterday. Yesterday and so far today I have had cramping almost nonstop. They're not severe, but uncomfortable and annoying. I keep checking and AF still isn't here. I do have to take progesterone supplements because my body doesn't produce enough. I have an appointment at the doctor to take a pregnancy test later this morning. 
Do you think the cramping is something to be worried about? I've had one other pregnancy, but it ended at 8 weeks. I never had this kind of cramping with that one. What do you think? Should I be worried??