How do I tell my mom I had sex

So I'm 19 but still live at home and have a decent relationshio with my mom but I wouldn't call it close. About two weeks ago I had sex with my boyfriend and then took the pill out of fear since we didn't have a condom. I don't know if I'm pregnant and I'm honestly panicking and need something to make me feel reassured that I'm not. What I'm trying to say it how do I tell my mom that I had sex and ask her to get me birth control even if I have no intention of having sex again. Any comment helps I've just been freaking about this for awhile now and need some advice.