Tubal ligation

I’m getting my tubes tied March eighth (8th) because other types of birth control are not safe for me. I tried having an iud put in but they couldn’t do it because of my retroverted uterus. And anything hormonal would affect my epilepsy meds. My neurologist wanted me to experiment with the pills I didn’t agree with that because I don’t want to risk having a seizure. So this was my last resort. My question is what are the chances of getting pregnant after a tubal ligation?