Heartburn is up higher in your chest, a burning sensation as if some food is about to come up. And yea mine already started....what is up with that?? With my previous pregnancies it didn't kick in until the baby was big enough to start pushing things out of place. I do know that pregnancy hormones relax the esophageal sphincter though and that's why some women get heartburn right away. I guess I'm lucky this time around.
I even had a dream about it...that my throat was burning and fiery liquid was coming up...