I couldn't have sex through the whole pregnancy.
When it was obvious I was going to have my daughter late the dr. suggested nipple stimulation to help get things moving alone. It didn't work and I was induced. Then later, when I nursed my daughter, sometimes I had strange contractions...not quite orgasmic but similar. Freaked me out the first time it happened. I later learned that it was common and it actually helped the uterus shrink back down to pre-pregnancy stage.