Telling the family

I'm 18 years old and 8 weeks pregnant with my first baby.. I'm very nauseous most days and vomit on most as well. I will be going on a 15 hour car ride with my family this next weekend. But I haven't told my family yet.

I've been with my boyfriend 10 months now. But my dads been in my life forever..

How do I tell my dad without him being dissapointed in me?

Any suggestions. ?