I want to add my response here, because it seems like most of the answers you've received already are telling you you SHOULD take on the responsibility of being this baby's father, if it turns out he is yours. I am ALSO going to tell you that, but I want to honestly address what you give up in becoming a parent, so that you really understand the magnitude of the sacrifice. Because even if everyone says you should do it, you are the only one who can decide whether you're able to meet the challenge. Based on my experience, adopted parents can be great, or they can be terrible, just like with biological parents. If you think you won't be terrible, then it's a far safer gamble for your child if he grows up with you. But anyway, here's my anecdote about becoming a (primary) parent, and the things it did to my life that I didn't fully consider beforehand:
Babies (especially small babies) are a huge amount of work. They generally need to eat every couple of hours (with my son it was 8-9 times per day). They also need a new diaper at some point after they eat, so that's about 8 diapers per day. When they're awake, they cannot be left alone, because they are so incapable of anything that even in very safe conditions they can find ways to injure themselves. They do sleep frequently at first, but never long enough for you to get really engaged in a mentally demanding project, so for the most part the best you can do while they sleep is to rest yourself, or maybe start a load of laundry and catch up on dishes. Or possibly read for a bit, or watch a movie with headphones on. Maybe the worst part, though, is that sometimes babies cry and cry and cry, and they can't tell you why, and you can't figure it out, and there's just no way to make it stop for a while. You'll also, of course, have to get up frequently during the night (that's the classic cliche of parenting that we see in all the shows and movies), and if you're the only parent, you'll be the one getting up every time. When the baby becomes mobile, he'll arguably become more work, even though his eat/sleep/poop cycle will be at less frequent and longer intervals. These are just some of the effects having a baby has on your private life, but the impacts on your public/interpersonal life are in my opinion even bigger.
Especially at your age, you likely don't have many (maybe any) friends who are excited about hanging out with babies. Even if they are excited about it, you'll only have a couple of options for hanging out: they can come to you and chat/hang out while you take care of the baby and do baby things, or you can meet them out at a park to walk the baby - as long as it happens before baby's 11am nap! - or you can talk to them on the phone for brief intervals. If your parents are available and willing to help you, you might be able to go out in the evening to a movie or a bar, but on the days they can't help you, you'll be stuck at home basically from 7:30pm on. Over time, your friends will get used to the idea that you can't hang out with them, and they'll probably stop asking. You and they will just be living in different life phases which are hugely incompatible in a lot of ways, and there's not much you can do about that. Your really GREAT friends, though, will find ways to stick around, and will keep reaching out to you - so you'll also find out who those people are.
Emotionally and psychologically, this is all much easier to deal with if you love your baby. But no matter what anyone says, there is no guarantee that you will, especially at first. You have a difficult situation in which you openly acknowledge that you do not want the baby, and that will make loving him a lot harder. I had postpartum depression after my son was born, so I can relate to this. I did not love my son. Dealing with his needs on my own every day pushed me to the absolute limits of my patience and far far beyond. I could see the person I had been absolutely disintegrating, and I couldn't see that any experience I had with my baby was worth that total destruction of myself. There was one occasion where I had to put him in his crib and go lock myself in my car in the garage so I wouldn't hear him screaming anymore, even though it wasn't safe for me to leave him alone. There was another time I got so frustrated that I kicked a hole in my bedroom wall. Another time I considered drowning myself because then I'd never have to be so tired again.
There is a light at the end of the tunnel.
Loving a baby is just like building a long term relationship with any other person, and as they get older, babies have more and more substance as people. Even if you don't love your son at first, eventually he will start to show you who he is on the inside, and you will not be able to help but love him, as long as you're there, and paying attention, and you receive what he gives you in terms of his thoughts and feelings and understanding. For me, this started happening around 18 months. My son is a compassionate little guy. He could tell when I was upset and he would pet my hand and smile at me and come give me hugs. He also was interested in things, and seeing his curiosity allowed me to remember what it was like seeing a butterfly or touching tree bark for the first time. Also, once he was able to understand the dangers of stairs (around age 2) he became a lot less work, because in many day-to-day situations he was able to watch out for his own safety. Our relationship became far less one-sided. Of course I still had to do everything for him, but "everything" at age three now no longer includes holding his fork for him, or changing his diaper, or picking up his toys. We can read together, and play soccer together, and sing together. We can even go out to the (child appropriate) movies together. And I love love love love LOVE him! Yes, it is still sometimes frustrating that I can't say yes when my friends ask me to be in a band or a play, because I just can't make that kind of time commitment, but they can come over to my house and my son goes to bed early (and stays there! Which not all kids do) so we can do grown up things after that.
As far as how being a parent has changed me:
1) I am much more diligent and on top of everything I need to do, whether it's related to being a parent, caring for my home, caring for myself, doing well in school, or doing well at work.
2) I am hugely more patient and even-keel in all situations.
3) I think and act towards long-term goals in a much more focused and achievable way.
4) I am happy.
I would say that becoming a parent, particularly when I accepted being a parent and embraced that role, it allowed me to become an adult in ways that no previous experience ever had, and I suspect no other experience really could have. I am very glad that I pushed through the horror of the first 18 months, and every day with my son gets better and better.
So: if he's your son, you would be depriving yourself of a golden opportunity if you give him up. However, expect that before it becomes a wonderful thing, all your worst fears about it will likely become real experiences for you. It will be HUGELY helpful to you if your parents are available to help-particularly if your mom doesn't work many hours or something like that.