Quoting Kaite Hylton:" People really make me mad, looking at me like I'm a screw up. Taking behind my back, and telling me I ... [snip!] ... breath. Being with us, is whats best for our baby. When you're in my situation, you make the choice.. Whats best for your baby?"
People react that way because you have no idea what you are getting into. But to be fair, most first time mothers don't, you don't know until you experience it.
Just let it roll off your back and do the best you can do. Finish school, work if you need to, and always put that baby first. It is possible to bounce back from poor decisions, but it's hard. REALLY SmUrfING HARD. Use their negativity as your motivation to be the best damn mom anyone ever met. But be humble, there is a lot you don't know (and that goes for EVERY first time mom) and take advice when it's offered to you. Don't get an attitude about it, you are going to need all the help you can get.