Pain during sex

Okay I know this probably isn't something people want to read but I've seen a lot of people are very helpful when it comes to others asking questions..ever since I have had my first child almost two years ago it is almost always painful to have sex. Not all the time but it seems like it's about 50% of the time when I find myself not enjoying the sex as much as my boyfriend because it just hurts. Has anyone ever had this happened to them after having a child? I go see my doctor on the 12th for a check up on my seasonal allergies but thinking I should bring this to her attention!