So I'm starting to show and..

I'm starting to show and I still haven't told my dad yet.. I live with my mom and we are really close but my dad on the other hand I only see maybe once a month if I'm lucky.. he knew about my previous pregnancy but I had a miscarriage and I'm just scared to tell him this time because I'm actually having a baby !! Any ideas or advice on how I should tell him? I really really need help with this I just feel like I'm gonna break his heart! His only child having a child at 18 ! Yikes !