heartburn during late pregnancy?

Morning sickness and heartburn was so bad during my first trimester & was more than happy when it went away in my second. Now, I'm 37 weeks 4 days and heartburn has came back to bite me in the butt. It started yesterday after a big meal in the afternoon (bad idea I know). But I woke up this morning and still have the heartburn and it's also making me nauseous.