Im 16 my is my 18 year old bf illegal?

im 16 my bf is 18 we`ve been together 2 1/2 yrs im pregnant my mom says if she even was to find out we r doing anything she`ll press charges what can i do regardless he`ll b here n my life forever my parents love him n they know nothing of our lives im only 3 weeks pregnant im telling them tomorrow u can also help with how i can tell them??????? what exactly will charges b and can he go to prison?idc what ppl think of me or about how my life is ''ruined'' jus answers please no critisism im holdin a baby now and i already love it