parents

Hey I'm 16 and sexually active with my boyfriend, he wants me to go on birth control because we have had a few scares here and there. My parents don't know I am sexually active and I prefer to keep it that way so I talked to my mom personally and said it was to regulate my period. Short story she told my dad and made it sound bad. And I'm not allowed to go on birth control, but I need too! What do I do?