I started taking birth control for the first time this month (the brand is Gynera and it's a combination pill) and I'm probably at about day 13 or so. however I find that sometimes I get a strange sensation in my stomach. It's not like a painful cramp, but a little "shudder" or a light cramp that disappears after a few minutes. I was wondering if this is normal? Like my body is getting used to the pills? Or maybe it's air, as I do have problems with air in my stomach every now and then (From eating at odd hours)