on monday the 21st is my due date is it safe to have sex before then?

yes u can have sex up until labor unless OB says otherwise :)

As you've already been told three times, it's true. And yes if doc/OB says no then no. Also other times that you should NOT have intercourse is if you are still at home and your water has broke or if it's uncomfortable for you. Don't push yourself cause you want to please your partner, your discomfort is not worth it. Have fun until then.

go aheah and enjoy it before the baby gets here. unless, of course, you have had complications and the doc told you not to. heck, you may even get things moving along a little quicker!