Is it possible for a penis to hit an IUD during sex? It feels like mine got jammed into my vagina walls last night & now its hard to urinate...

Sort of... Since the iud is in the uterus, the penis won't hit it directly during intercourse; however, it is common depending on anatomy, the comparative sizes of the partners, and the vigor of sex for the penis to hit the cervix, the opening of the uterus, or compress the uterus. Usually that should not cause a problem. If you are having symtpoms, or pain, you may have a UTI which can happen after sex.