I am in my third trimester and the minute I cough, my lower stomach area starts hurting. Is this normal?

Yes it is normal, as by this time, your muscles have stretched a lot to accommodate baby. Often it also leads to soreness, and when you cough, the pull in your muscles causes the pain. Do speak to your doctor avoid it. And once your baby is born, you will soon notice that the pain has disappeared. Take care :)