I have a problem.

So my family has forbid me to see my boyfriend but mind u I'm 19 going on 20. So we had sex tonight. I had to leave the house because of my anxiety but managed to meat up with him as well since it's been a week since we last saw each other. But after we did out business I looked on here to see when my next ovulation date is. ITS IN THREE DAYS!!!!!!!!!!!!!!! Now I am scared. What do i tell them if i am pregnant. They already told me that I cant be at the apartment if I am still with him but they dont know I am. He and I live in two different towns but work in the town I live in so it makes getting together sort of easy. But back to my point. What do I do if I am pregnant. I cant just say "hey I'm pregnant with the guy you hates child. Can I keep it." I get I'm almost 20 and I can make my own choices but what do nbn I do about this. Like I am legit scared for my life. Help me please.