Please help me on my situation, really confused!!?

Okay so my situation isnt too good. I understand most people will look down on me for being so promiscuous and stupid, but I can honestly say I didnt expect to get pregnant as I had unprotected for about 2 years with nothing. Its my biggest regret getting myself in this situation, so lectures are not what I need. I want some advice on what I should do. I found out a week today that I was pregnant, Im about 6 weeks pregnant. Im in a tricky situation as Im not a 100% sure who the dad is. I had with one of the guys 3 times twice after I conceived, and the other guy once before I conceived too, so that means there is half chance between the two guys of being the father? Is there anyway I can find out before birth who is for definite? Thats my first dilema, the second, Im not too sure what I want to do with this pregnancy. So far the guy Ive told is the dad or who I thought was wants me too have an abortion, he cant afford it he says. My mum and stepdad want me too have an abortion, and so do my grandparents. I feel really pressured by them into this but know its for me they want me to do it. I feel as though they are a bit biased towards this and arent really explaining my other options. I have said too them I dont really want an abortion much, my friend had one, and I know most people do regret it and struggle emotionally after. Im scared for my mental health afterwards is the reason I dont want, but they dont know Im suffering from depression just now. I dont necessarily want a baby just now either. Ive looked into adoption briefly, think its a possible solution, but dont feel I would be able to give my baby away at birth, and cant find any useful adoption agencies in UK. So Im in a dilema. I think I would be able to cope with a baby, but my mum has just made it sound so bad and terrible, saying that I would be living in council accomodation forever off benfits and my life would be over basically where truth is Im very determined and know Im going to have the career I want when Im older. Last night I felt under great pressure to have an abortion and agreed to have one to satisfy them, if I do they are going to feel really guilty about the pressure they put on me. If I keep it Im worried about how they will react because I know they do love me, and dont want my teenage years to be thrown away, so I will feel guilty about not listening to them. Ive just turned 17 last week, Im single, not got an income, and in college just now, but would be finished before the birth. Please help.