TMI position

This is my 2nd pregnancy. With my first pregnancy I had a very high sex drive. So we did it a lot. I never had any cramping or bleeding. With my current pregnancy I just started to get my sex drive back. We decided last night to have sex after not doing anything for 16 weeks now. After when wiping I noticed there was some blood. Not a lot of it though. Is this normal or should I be concerned? Also sex is super painful this time. My fiancé has a very large penis so I think that could be why. Can anyone suggest some positions that could help eliminate some of the pain?