Pregnant & 21

Hey guys I’m looking for support and advice I’m 21 and pregnant I have a 6 year old and I’m together with his father we were high school sweetheart and like all relationship its been a little bumpy but we are still making it together 8 years later. He’s supportive and positive we can make it and it’ll be fine. I’m just worried I don’t have a set in career I still go to school and I work. I live with my mother and he lives with his family. I’m just worried on what to do, I started to see a OBGYN and I get my first ultrasound tmrw. I cant help but to think maybe we shouldn’t have another baby we’ve had issues on trust a few months ago and it’s hard to let go or move on. But I’m not sure if I would be selfish to keep this baby and bring it into a relationship that may not work. Or if I would be even more of a terrible person to have a abortion. It’s really hard and i have been constantly nauseated and sick and stressed out. Any advice would help!