Pain during sex

I know some pain is to be expected at sometimes. But if he goes in certain positions it feelsike he's hitting a hard bone inside of me. He can feel it as we'll and it actually hurts when he hits this "bone" does anyone else feel this "bone" or is it something I need to have checked out. I really can't remember if I've always felt it and am wondering why this might be a reason I haven't gotten pregnant after 6 mths of TTC. I have conceived over 16 times and never ever has it taken over 1 mths