I've had paragard for 6mnths & still have a yellowish smelly discharge and is potent during intercourse. Is this normal and what can I do to stop it?

Get tested. I agree with dr proffitt. This sounds like an infection and is probably unrelated to the iud. Smelly discharge that is worse with intercourse is most likely bacterial vaginosis. If testing confirms then it can be treated with antibiotics. Women without iuds get this too.
Infection? An iud is a foreign body in the uterus, though it has a purpose and is properly used and inserted. One can get infections. A yellow and foul discharge is a sign of infection. You should see your pcp/gyn and have an examination and proper testing and treatment for the symptoms your are expressing.