Periods pains after baby?

I have two children. I never experienced this after my first.

My youngest is 8 months old. Ever since he was born, I have noticed a pain while on my period. It’s not cramps, even though I still get those. It’s like the labia maybe?

The only way I can describe it is that it’s the same sore feeling I had after having both of my babies. It feels stretched and sore.

Is that normal after having a baby? I didn’t work my first. I highlighted the area in this graphic.