What should i do?

Ok...so last night I took a pregnancy test & its positive & we couldn't be happier but here's the part I need help with....I live with my boyfriend's grandparents & he wants to tell them tonight but they don't like me as it is (I have no idea why) but we just found out & I've told my mom she is happy but she said to wait to tell them i wanna tell everyone but I know if I tell his grandparents they could kick me out but they say they want me out but they don't do anything about it.....I shouldn't say anything until I move out or no?