Try new things. Talk to your SO about your feelings and that you do not want him to feel like that part is gone forever, just temporarily difficult for you. Pregnancy can really throw your hormones and emotions into a tailspin. Most days sex just sounds like a chore, but some days, especially closer to the due date, urges may reappear. My doctors always said sex is no problem during pregnancy and I should try whatever I can.
Just after birth though (with ALL 4), I really did not want to anymore. That could last more than a year if I let it. I had to ease back into that game and work up to the levels of enjoyment we had before. Over time we just tried a lot of new things and new positions, porn types, lingerie, and LOTS of open and honest discussion about our current feelings and fears.
at 8:57 AM on Sep. 14, 2010