telling parents

I think this is the scariest part for me. I'm 18, currently enrolled in one of the top university's in Canada, while my s/o (of 5 years) is also enrolled in the same university. I'm 18 and had not planned this at all, I was on bc, and we used condoms as well! I'm not sure how to come out to family as i know they'll be disappointed in me, and I'm scared.... anyone have similar situations or any advice? I mentioned the university thing as my moms biggest concern was me staying there to complete my degree since I've been offered full scholarship :/ !