Is it normal to have wet underwear in the third trimester?

Yes: In the third trimester you may sweat more. Leak some urine, and have a lot more mucus production which causes wettness. Talk to to your doctor though to make sure it is not amniotic fluid leaking.

Yes: The mucous discharge in the third trimester increases. It is also normal to leak small amounts of urine. If the discharge is heavy your should be checked for vaginal infections and to make sure you are not leaking amniotic fluid.