How do you tell your family about some unexpected news?

I am 22 and I am engaged. But last week, I found out that I am pregnant.
Seeing as my parents are very devout Catholics, and believe that sex should be after marriage, I think that they will be very upset with me, and won’t talk to me for a while.
I personally am very excited, and I really want my parents to experience my joy.
Please help me out! Any suggestions will help.