When should I tell him!

So I am in love with this guy we have been together for 9.5 months. We know literally everything about each other. Had sex the whole lot. The thing is we never have said i love you. My parents don't know about him and can't til June 8th when I graduate. I know he cares about me allt and wouldn't try to hurt me. Should I tell him that I love him in June 8th tht is when it would be exactly 1 year.