Okay mommies, questions about cramping?

This is my second pregnancy I'm 4-5 weeks along and found out Saturday at 12dpo, my first pregnancy ended in a miscarriage at 5 weeks 6 days so I'm very cautions to every ache, pain, twinge, or cramp but (with my first it didn't show on a pregnancy test until I had missed my period for TWO MONTHS!) so my question is what kind of cramping is normal? I have mild cramping (just enough to notice) in my uterus area and it worries me because of my previous mc. And also can gas ( sorry tmi) cause sudden pains in your upper stomach? I need some words to ease my mind. Have any of you mommies or mommies to be have cramping and still carry a healthy pregnancy? My prenatal appt isn't until April 29th which I'll be 9-10 weeks then so I'm super nervous but trying to stay calm for the babies health. :(