What do abortion clinics do with the fetus remains?

Im currently 13 weeks pregnant and have been contemplating abortion as I already have 2 kids and I just don’t feel supported by him I think we will be breaking up.

It’s a hard decision for me to make I don’t want to but I feel that I have to I just can’t imagine coping with 3 under 3 on my own.

He already doesn’t do much to help me physically or financially.

I’m also curious on what they do with the baby once it’s out. I just feel so guilty.