I had a lot of cramping with my first pregnancy and very little with my second. This pregnancy, I've had hardly any cramping at all. It is very normal and I assume very common with your first as your uterus hasn't been stretched out yet. =)
Heya cramping is normal as long as its not severe in pain or followed by bleeding, its most likly things stretching getting ready for the baby I had it for few weeks its easing off now, we had a us yesterday and baby is doing great. I hope I put your mind at ease a little x