TELL YOUR PARENTS!!!
They may yell, they might not. They might say some very hurtful things. Unless they are completely heartless, eventually they will calm down and want to help you.
As for the father, honey, if you don't feel you should be with him, the worst thing you can do is stay together just because of the baby!
You say you're not sure!
All you have to ask yourself is, do you see yourself raising this child and building a life together with this man
If you feel there is a chance then give the relationship that chance.
If not, then get out and figure out what you want!
I know it's scary but you have to do what's best for YOU right now!
TELL YOUR PARENTS!!!!!!!!!!!!!!!!!!!!!!