Josh - I was a midwife apprentice, a doula, have attended probably 300 births, and this is my fifth baby. Trust me when I tell you - having sex during pregnancy under normal circumstances does NOT hurt the baby. Whoever wrote the story you read was seriously misinformed.
Now, if you have your own phobia about it, that's your thing to deal with. But pregnancy is quite very directly related to sex, a very normal part of the whole process, and in fact, all the hormones that get the baby IN there (i.e. oxytocin) help cause the contractions to get the baby out. The contractions of labor and the contractions of an orgasm are quite similar.
I wasn't saying you weren't experienced or not believing your words
if anyone saw their parents having sex they would be out of there in a hurry