My oldest is still a lot younger than you but on the edge of puberty and almost a full pledged teen
.
That said, he has lots of questions.. and I try NEVER to deter them. When he asks, so long as his siblings (who are much younger) are not around my dh and I will sit down and be totally real with him.
He has said on more than one occassion he is glad that we'll talk with him (candidly) and that he feels he could tell us anything.
He is wanting to get a purity ring for his birthday.
Anyway, how to approach your parents? Set a date, let them know there's something you would like to discuss. Maybe your parents think that you know what you should know and that's the end. Let them know what your struggle is.
Oh and YES, I would want to know if my child was having sex or not.
(((HUGS))) to you!