I had/still have intermittent cramping, much like period pain. Freaked me out so googled it and apparently is normal, just things stretching. Have asked several friends who have recently had kids and they all pretty much say they had it too. Some of them throughout entire pregnancy and sometimes quite bad. But how is this for strange, when I mention to doc/scan lady, get a blank look and an oh well. Also got the same response from mum. Have put it down to maybe age? Am 33 and first pregnancy so all my "gear" has sat around for years "getting a little rusty" Maybe??? Also am horserider so have been using stomach muscles for last 25 odd years, maybe they are set in their ways.
One website did say to make sure you are drinking enough water and I have found that on days when I have been a little slack in that department, they have seemed to be worse.
They do, however, seem to be easing up. 12 1/2 weeks in.