So shes not on birth controll, and doesnt use condoms because she wants a baby, but shes afraid to tell her dad if she is pregnant...
You could do it in a cute way...(this is what I did) I bought a baby bib that says "i love my daddy" and put the pg test inside the tag.
You could write him a letter if you think hes gunna explode on you, I get my feelings out better on paper.
Or just tell him, face to face. Ask him "what would you do if I told you I was pg?" he will ask you why (and then tell him) or state his opinion (and then you still have to tell him) but at least youll have an idea of how he is going to react.