What's Your Intake On This?

So my son's father and I broke up before we found out I was pregnant, (My son is now 1 years old). We were on bad terms for awhile, but then reconciled a few months ago and he's a great father. Well I decided I did want to take that step and be with him and have our family, only there's a couple problems. He has a girlfriend and another baby on the way (which he didn't tell me before we had sex or for that matter, for a long time). So, I'm not okay with the fact he had a girl pregnant when our son was only 5 months, but to still claim your girlfriend, but still wanna see me too? I have a problem with that. He tells me I'm not going anywhere and bullshit like, you were first. But honestly I know my self worth. But what do you think about all this? Can he really be in love with his gf now? Can he be in love with me and her? I don't think so...but apart of me feels that he really wants to be with me, since he spends most of his time with me. Like days at a time. I know I deserve better, but he was the one who showed me he really cared about me and still does. I'm so CONFUSED. AND VERY EMOTIONAL ABOUT THIS SITUATION.