My lower back hurts because of the posterior uterus ㅠㅠ

The obstetrician told me when I was giving birth~

The uterus... because it's a posterior uterus, you might experience back pain later.

But I really didn't know much before childbirth,ㅠㅠ

Since giving birth, I've been experiencing ovulation pain and menstrual cramps...

My back hurts more than my stomach pain ㅠㅠ

Did I sleep badly? Why does my back hurt so much... and then my period starts soon.

Since the uterus is positioned towards the back, how do those experiencing back pain manage it?