You are very young to be in this situation, its hard enough when you're a lot older, you must be going through hell. At 16 he maybe is feeling very scared as you must be, about the fact that you are bringing a new life into the world. Maybe that's the reason he is with this other girl, because he cant deal with this hard situation, and is trying to pretend it is not happening, You say he cares about the baby not you, which must be very hard to take, its very upsetting to be left alone while pregnant. You have to try and get on with having this child in as calm a way as you can. Its stressful for the child growing inside you when his or her Mother is so stressed out and unhappy. It may be that he is just very afraid at the moment about becoming a Father, and after the child arrives will see that he is making a mistake by not being involved more at this time. hopefully it will work out for the best for all of you, and I wish you all the very best.