I have experienced this with all four of my pregnancies and it has thankfully so far, never been anything to worry about. It is very common after sex and can be caused by the erosion of the cervix, which I think is harmless. It is still very important to go to the hospital every time it happens though to rule out any problems.
Hi some one told me it means a miscarriage is on it way don't know if that's true though
35 weeks is not a miscarriage as you would have a live baby albeit a bit small. The first answer is correct, always get it checked.