Okay, sorry, I'm getting carried away in a romantic notion here which isn't helpful to anybody.
Point is I have been through pregnancy and young-single-motherhood and uni and all of the rest of it and it is hard. I wasn't as young as you are (I was 19) and I'd already moved out of home and the pregnancy was sort-of planned (although I had no idea what I was getting myself into at the time despite thinking that I did)
A baby won't end your life and it isn't a disaster. You will love it and it will give you a sense of purpose and keep you going during the darkest, hardest times and it is true that the feeling of unconditional love is incredible and like nothing else.
But - what it is really going to be like is that the baby is going to put huge speed humps between you and the life goals you might have if the child was not around. You will still be able to reach them, and I would absolutely support you 100% in going for it, but it is going to be so much harder going over all of these speedhumps and potholes in a rust-bucket of a car, especially when the road you're on is right next to a fast motorway where your friends and other peers are zipping along towards their goals without a care in the world or even noticing how hard it is for you most of the time. It is hard to study, it is hard to learn all of the normal 18-year-old stuff like how to fend for yourself, balance bills and other expenses, keep on top of all the housework without running out of food or clean bowls or socks, you don't have the option of going through a few disastrous relationships to work out what you actually want from a life partner (because you can't just move someone in to see if you get on, moving in basically means stepfather-ing and acting as though you are married which means you're stuck with a weird serious-relationship-but-not-living-together thing until you are ready to basically be married)
- However hanging around on the MN relationship boards is an excellent alternative to dating loads of tossers and tends to improve your standards beyond recognition IME
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And when you DO find someone you want to be a life partner with it's all difficult because you've already done a lot of the things they were always imagining you'd do for the first time together, and you will both find that hard. Career wise you will feel torn between wanting to compete with others at work and wanting to be there for your child (although it's much less of a career hit to have a baby now than it would be in 10 years) You may also feel stuck in the area that you live now if your child has contact with his/her father. When you come to the time of your life when you want more children that will be a wrench because you'll worry that your first child will feel pushed out or that you have let them down because you struggled more, naturally, by being on your own as opposed to being in a supportive partnership.
I haven't covered any of the usual like the not being able to go out, the sleepless nights etc, because you know all of that and that might well be a sacrifice you are willing to make - I'm offering you a more realistic counter to the hysterical "Your whole life is ruined!" wailing that you will presumably encounter from at least one angle at some point. This is the real sacrifice, not a short term one of sleepless nights for a year or having to miss out on a few dates or parties. It will affect your whole life and the lives of your future potential husband and children too. It is doable, it is copable, it is far from the end of the world but it is a big, big thing and far bigger than you are probably contemplating at the moment. I would never tell somebody what to do and I would totally respect your decision if you read all of this, think it through and still decide to have the baby but it is very common at 16/17/18/19 to think "I could never live with myself if I terminated the pregnancy" and not think about how you will live with yourself if you continue with it.