Heartburn?

Not sure if this weird feeling is heartburn but its like a burning feeling around my ribs. I had this before and I think its my uterus expanding upwards.  I felt Zev recently which was super exciting, I was a little worried cause all I feel is Zola moving around. Zola is higher up then Zev and I still think she is breech so maybe that is why I feel her every 30 minutes. She is VERY active, I wonder if their behavior in the womb reflex there personality later in life. Zev is going to be like Jacob, which is mellow and Zola is going to be like Arie (my step-son) which is a little more hyper, he always has so much energy ^_^ I want a little calm girl. I don't think I was bad as a kid, spoiled maybe but not bad. Jacob acts like me, when I was a child. ^_^