unplanned pregnancy and unsure

I just found out I am pregnant. we have three kids and my postpartum with my third was medically and mentally complex. we had been using contraceptives so this is a very big surprise and we don't know what to do. I was also on a medication that you can't take when pregnant and the baby (if we decide to continue) would have to be monitored for heart defects.

any advice? my partner is very overwhelmed by the thought of an abortion.

*if I could be less worried about my and baby's health this wouldn't be a consideration