What could it be ?

So I'm 36 weeks pregnant and for the past two days my Vigina hurts when I try to get up or move. It hurts as if I was having a rough sex , but I didn't have sex for more than a week now. I went to see my doctor on Friday and he said that baby I already low buy I'm not dilated yet. Does it hurts because he is low ? Could it be something else?