I have had all 5 of my kids naturally and had stitches with some and with others I didn't. It always hurts me the first few times. But my husband is very very careful. Like justice said, you may want to use some sort of lubricant.
I am shocked that your doc didn't check you though. My doc always does a pelvic exam for my 6 week check-up. If it continues to hurt for much longer, I'd go back to the doc and have him/her do a pelvic exam to make sure you are okay.
Now this was 10 years ago....... but i do remember it being painful after 6 weeks (i also had stitches) with me too.... it made me not want to have sex at all.... so i waited LOL for like 5 months (probably not that necessary to wait that long) and when i did it again with plenty of lube it wasnt that bad..... I think some women just take a little longer to heal than others.....