Not sure how to tell my parents 😕

Today my boyfriend and I found out we are expecting our first bundle of joy and of course we are overly excited about it. But the thing is, is I'm 16 he just turned 20 ( please don't judge, we have been together for three years and it's not illega.) my mom got pregnant at 15 and had three kids by 22. But in just not sure how to tell her that we are expecting a baby now. I know I know I'm only 16 please don't judge me on that either. But I am about to graduate high school early, I have a job and he has one too. I'm not new to having a baby i helped raise my nephew and he is 5 now. But if there's any ideas on how I could tell my mom and dad and not be so nervous about it please help me!