I wouldnt worry too much but if your concered i would get checked to put your mind at ease. Could it be lightening crotch? As that can be quite painful and its like having a really sharp pain going straight through your pelvis area. Or could be ligaments when baby is moving around when you dont realise. I get all these. But if you are really worrying then speak to your midwife and she should reasure you x
It can be perfectly normal but i would still get checked out just to be safe