I'm recently a new mother and my little girl is only four months. Her father was in her life for the fist 6 weeks regularly. Now that I decided we weren't going to make our relationship work he has been in and out of her life since. Starting back to October. Every time he gets upset with me on issues not concerning her he disappears for two to three weeks at a time. This last time in the lasts 3 1/2 weeks he hasn't seen or called to see how she was. Today out of the blue he calls and wants to see her. I just would like to know how long I have to wait before I can say that he abandoned her or how long it would have to be before it was considered abandonment. I Live in Pennsylvania so I know the laws are different everywhere. Please help.

Even if he totally disappears for years you can not 'get him for abandonment'. You can file for sole custody and if he doesn't go after visitations or joint custody then you have no obligation to let him see her.

Well the custody issue is another thing. He is on the birth certificate and pays child support but only see her when it is convienent for him. But since she lives with me does that mean I have soul custody and if he wanted visitation he could take me to court for it. Or does he already have some sort of custody?

You do not have to let him see the child until he gets the court order visitation. Then if he wants to see her when it is not his time you have the order backing you up that it is not his day.
I am sure that if there was some custody issued you would have a copy. Right now you do not even have to let him see her but if you make it too big of a problem he might go for the support order.