Having serious problems!!

Ok, hi. I'm not sure if this should be in the sex forum or not but i don't suppose it much matters. My boyfriend and I are quite serious and are both wanting a sexual relationship. We've tried on several occasions but he just can't seem to get inside me. It does hurt me a little bit but it's not the pain stopping us its just that it won't go in. It's not that embarrassing for us but just a pain in the arse. I'm worried that there is something wrong with me and was wondering if anybody else has had this problem. Is there something worng with me or is he just too large and i need stretching? Thanks. :mad: