well, not quite the same situation as you - but very similar - my DP and I were living on different continents (for work) when I found out I was pregnant - this was in January this year, just after I got back to my job after christmas in Britain - and at first there were a LOT of tears from me, as I didn't think we'd cope. It wasn't an ENTIRELY unplanned pregnancy, just unexpected (we did not expect to conceive on our 1st and only try, let's put it that way!), and he lost his job when I was 8 weeks pg, then I handed in my notice on my job overseas so I could come home (which we kind of planned anyway), so for a couple of weeks it looked like we'd both be unemployed, and that was a very shitty time. However, I was offered a job back here (sitting at my desk typing this actually ), his company got bought out, and in May I moved back, started my new job, we found somewhere nice to live, and now I have just under 4 weeks left at work before mat leave starts! So you can probably guess, I chose to keep the baby (who just gave me a hefty boot in the ribs, in case I'd forgotten his presence in the last 10 minutes )
I'm 27 now, and do feel a little like I'm playing at being a grown up, but I'm in a very stable relationship, my DP is (now) delighted that he's going to be a dad, and we're both just counting the days until baby arrives!
So what I would say is - give it a couple of days, speak to your DP about it, and really think about what you want from life. Oh, and read as much mumsnet as you can, I've found it very useful when having a panic about anything - although it can on occasion raise the blood pressure a little, it's generally a great source of advice and hand holding.
Good luck