Pain in the belly

I am 12 weeks pregnant. Since almost 2 to 3 weeks, if I turn abruptly in the sleep or while walking or while sitting or doing anything, a sharp pain occurs in the lower part of my belly like someone twisted my skin... is this normal? Pain lasts only for a few seconds though. I was convincing myself that it might be normal as the uterus grows... but am also concerned if its too early ... any suggestions?