You don't need to stop unless you have complications (and if you do, your doctor will tell you to stop). Having a lot of discharge at the end of pregnancy is normal =) TMI but I'm usually wayyy moist down there before we even start having sex! lol Personally, I wouldn't stop. I had sex like at least 3 times a day when I was pregnant with my daughter.... and she was a week late!
Good luck! And remember after you have your baby its 6 weeks without any lovin', so enjoy it while you can!!