my boyfriends mom...

I am 16 and my boy friend is 17 in 2 months I will also be 17...we have been together for nearly 2 years and we have had sex, today his mom found out and is making it to where I can't see him out side of school, even worse she is telling my mom and I don't need her think I'm a disappointment, my mother and I have this bond that is more like best freinds than mother and daughter. 
I think she shouldn't involve my mom because it's my responsibility to tell her when I think the time to tell her is right, she always stressed anyway and I don't want to add anything on, as soon as I think she is ready to know, I want to tell her. My boyfriends mom won't listen to me and is about to call my mom.
Please don't tell me I shouldn't be having sex or anything like that because it is andesision I made, I'm aware it's a stupid one (to most) 
Am i in the wrong?