When baby comes you can file for child support, but unfortunately until then I don't think there's much you can do. Your parents could charge him with statutory rape as you're a minor, because having sex with you was very wrong of him, you're half his age. It sounds like you still love him so you probably won't allow that, but I just think you should reevaluate if this guy is worth it. He preyed on you and that other girl, he used you, and I'm very sorry that happened to you. Your best bet now is to see if your parents or any loved ones can help you out until you can get on your feet.
Do some research too, see if there's any free family prosecutors in your area, if he left you with nothing you might be able to file a civil suit for something similar to alimony. I hope everything works out for you, you deserve way more than that guy. Good luck! You still have plenty of time before baby comes to figure it all out so try not to stress too much
Unfortunately, you weren't married so there isn't a whole lot of legal action you can take. He could be prosecuted for statutory rape depending on your states laws and the age you were when you began having sex, but you would need proof. If he went to jail, you would not get any child support from him.
So, you are really in a jam. I am sorry for that. You are going to need to figure out a way to get some job training and earn your own income. You can get child support from him but it is not going to be enough for you and a baby to live off of.
If you're in the US, you can sue him for child support whether or not you are or were married.
I don't know what state you live in, whether this was felony statutory rape or not.