Heartburn?

Alyssa • A Corrections Officer and Dispatcher, I am happily with my fiance, soon to be husband. We miscarried November 5th, 2015 with our 1st, I am pregnant...again! Hoping this one makes it. I'm very excited!
So I woke up in the middle of the night, I felt like my stomach was literally all fire inside, but it felt like I just did a million crunches and my sides and back were outrageous pain. I am thinking that maybe it was bad acid reflux or heartburn. Any of you ladies experienced this before? Is it heartburn? I'm only 6 weeks pregnant and I'm so sick all the time.