How to tell my mom i’m pregnant?

I’m 20 years old & I just found out yesterday that im pregnant. I wanna tell my mother but she’s caribbean and i know she would definitely kill me if i ended up pregnant and we’re at that point so, i want to know how i can tell her . She was 21 when she got pregnant with me and had me at 22, so Im hoping she’ll be more understanding considering that fact but I’m not done with school and I really want to be able to finish school, if it means i have to carry my baby with me. any suggestions?