Does breastfeeding help your uterus shrink?!

Ari

Newly PP and was told that while BF your uterus will have contractions and be shrinking down in size?!

Is this something any momma has heard? If so how long does this take usually?

How many calories are burned with BF?

I have felt pretty uncomfortable contractions while BF but I thought it was gas or maybe the way I was sitting since I'm new to all of this!

Thank you!