I was 19 when I fell with my first child. A few days from leaving for the military and had only dated the father a handful of times so no relationship.
I gave up the chance of my career (the military forced me into a corner) and became a single parent. It was hard because my whole life changed beyond my wildest expectations. I had minimal support. I ended up working full-time and spending all of my very low earnings on childcare and rent. I had no money for myself, ever. I had 2 or 3 outfits for work and a couple of pairs of jeans and t-shirts. No nice clothing, day trips or holidays. I didn't comprehend at 19 that by making the decision to give up the opportunity of a career and financial independence to have a baby that my life would become so harsh. Not just for me but for my child too.
You NEED emotional and financial support being a single parent because the toll can be damaging without support and I've not known many single parents who earn decent salaries which supports them plus children in a decent lifestyle. The evenings you can't go out because you can't get a babysitter, the invitations that dry up from friends because they view you differently now. You won't belong in the couples groups either because that just reminds you that you're a single parent. It's a strange 'in-between' place of existence, once which I found incredibly lonely and isolating and led me to depression and over-eating.
Are you ready to give up your degree? Give up the chance of establishing a career for yourself, the opportunity of giving yourself the keys to financial independence? Give up your carefree social life? Give up single-life travel with friends? Are you prepared to give it all up for potential loneliness, constant washing, baby-feeding, interrupted sleep, potential financial dependency on others, saying goodbye to your body as it is today? Every single day for the next 18 years you will put the needs of someone else before your own. Everything you know your life as today will look completely different this time next year, everything. The dynamics of all of your relationships will change too.
Your life WILL change for ever. The question is will it change for the better or worse? Your boyfriend has made it clear he will not be there to support you both, he wants his single life. If you are harbouring thoughts he may change his mind then err on the side of caution that he will NOT. Then when that becomes clear you will have the fallout of a relationship break up to deal with as well as a pregnancy. Have you read on Mumsnet the difficulties between parents when relationships break down? It's horrendously painful and casts a shadow over your life for years. Women need men to raise a baby but you are very young to be contemplating giving up your freedom and lack of responsibility without having your ducks in a row.
How will you support the baby financially? If you have to return to work full-time will you be able to afford the childcare on your single salary, bearing in mind the salary scale for someone with no experience or qualifications. If you decide not to return to work then assume a life on benefits? Unless your family is financially able to support you and the baby.. don't assume you will get maintenance from the father, they have their own ways and means of avoiding that.
Then you've got the whole blended family thing when you eventually meet someone who won't be the baby's father. Make no mistake the dating pool when you're a single parent is reduced in quality! I met my now husband after being on my own for 13 years and have dated some pricks who were just on the lookout for vulnerable single mums (yes, single mums are a vulnerable targeted by pricks).
Having said that, if you have a loving family who understand your situation and will support you with whatever you need then it may be ok.
There will some who have been successful at being a single parent and that's really great for them and their children, genuinely. But the majority of single parents struggle for years emotionally and financially so it's really important that when making your decision you look at the reality of your life rather than how you hope it will be. Nobody else will be responsible for the baby except you and the father and if he is not a willing participant then it's solely down to you.
I don't want to patronise you but 19 is very young to become a parent (because of what you will be giving up). If I had my time again I'd wait until I'd established my finances and was in a relationship where we both wanted the same things.
Good luck in whatever you decide.