When i have sex there is sometimes a popping noise. like my partners penis hits something. it hurts so bad. what is going on?

Painful Sex: Otherwise known as dyspareunia, pain with intercourse can be caused by many things. Infection, poor vaginal lubrication, endometriosis are a few causes. In your case your partner may actually be hitting your cervix causing the noise and the pain. Changing positions, such as with the woman on top, gives you better control and less likely hood of this occurring.