My ex girlfriend is having my son - California?

While we were dating we had both talked about moving out of state. In November of last year she broke up with me. In December she called and told me that she was pregnant. We talked for a few weeks and I told her that I still need to move, I had already made custody agreements with my ex-wife and be close to my 3 year old son. The last I heard from Jenny. (Thats what we will call my ex gf) She texted me and told me that I was never good enough for her. I moved out of state in Feb of this year and gave her my new number. I have contacted her periodically and told her I want to be kept informed. She is no trying to say that I abandoned my child and that I do not deserve to know. I have messaged her and tried to be civil about this, but she always turns hostile and defensive. I don't want to fight. I just want to be part of my childs life. Does anyone have this kind of experience. Lawyer, Paralegal, or personal experience. I am now legally obligated to stay where I am, (custody agreement wife ex wife) What can I do? Jenny has some very powerful friends and I don't know what to do!!