problem in the bed...

so the other day me and my boyfriend were having sex.. we have a 12 week old and so it is something we don't do often anymore. well something happened that never has happened to me before.. I couldn't get wet.. he noticed and got kind of worried. asked the tipical questions, "are you cheating on me" no babe. I'm not. "do I not turn you on anymore" now this question. I think my man is sexy and very attractive so do I find him attractive? uhhh yeah! I'm not sure what in the world was going on though. I was actually really embarrassed and have been trying to figure out for days what it could be.. the birth control shot I'm on? really tired? maybe because I thought I heard the baby? I'm really not sure why I couldn't get wet but I was really embarrassed. any thoughts lady's?