I've had 1 live birth and 4 miscarriages and I had a lot of cramping early on with my son but didn't have cramping untill after I started bleeding with all the miscarriages. As long as your not bleeding everything is probably just fine and even if you start bleeding you can still go on to have a healthy baby.
I am 5 weeks with my 2nd child 3rd pregnancy and I am having exactly the same as you! Still petrified as my last 1 unfortunately ended in miscarriage. Thought I'd post and see how you are getting on?
Cramping is normal as your ligaments are stretching to make room for bub. I am 13 weeks now but got cramps like I was getting my period on and off since week 6. Anything that is too painful to bear get checked out