Hello Dr I went down a water slide 4 days ago. I was laying arms crossed over chest I was flipped on my arms and lost breath I have a pain in the side I was flipped heart side when I push on it it gets worse I am breathing fine and heart rate fine?

First of all. it sound like you bruised your ribs (and possibly displaced the cartilages which attach those ribs to your sternum (breastbone)
Secondly what's a 31 year old doing sliding down water slides...your bones are not as flexible as a child's!!!!

Hope this is helpful
Dr Z.