What is the difference between uterine contractions in orgasm, periods and labour?

Belle: What is the difference between uterine contractions in orgasm, periods and labour?
The womb contracts during orgasm, period cramps and childbirth. But why is it all so different? It feels amazing during orgasm, but AWFUL during periods – and I do not know but can imagine what childbirth is like. :S. Why is this?

Answers and Views:

Answer by ~ <3 ~
well, it takes place in the same area, but each has a different cause or purpose. it’s all serving the reproductive system

Answer by Jessica
It is because all of them are different purposes. Also, different things are happening with your body….