Child support

So my ex broke up with me last week and now I'm wondering what I should do. I'm 30 weeks pregnant. He said he wants to be involved and told me he plans on making a custody agreement like he has with his ex wife (he told me this a while back as an if we ever broke up kind of scenario because I think he's been wanting to break up with me for a while now). Well he gets his daughter every other week as they have a 50/50 agreement but he doesn't pay child support to his ex wife. My question is should I still try for child support? I only work part time where he has a full time job as well as a mechanic business on the side plus I am now going to be a single mom of 3 and I already know I'll have the baby more often than he will due to his job. He's a good dad. I don't want him to think I'm being petty because I'm not I just know I'm going to struggle. This baby was very unplanned and I'm currently living with my mother til I can get back on my feet and now I'm going to be struggling even more to do that. This was very unexpected. I already receive child support from the father of my other children but we don't have a custody agreement and probably never will so I've never dealt with that. I live in Florida. Should I talk to a lawyer?