4 weeks and cramping: Question!

I know the best thing to do is ask my doctor. However they won't see me until I'm 10weeks. I have read online thay cramping at 4 weeks is normal. But I've had cramping on and off since 7dpo. I'm not 4 weeks and 2 days pregnant. This is my second child and I never had this with my first pregnancy. Has anyone experienced this before and go on to a healthy pregnancy? I am terrified of having a miscarriage. I am not bleeding just period like cramps on and off. Thanks in advance!