Dude, if you're still worried, go down to the pharmacy and inquire about the day after pill. That will sort your problems with worrying. By the looks of your posts, it's not too late! I am a guy also and it does get really stressful for you as well as your partner, it's even more stressful if you both want to be partners for life like myself and my gf. I doubt you would have gotten her pregnant mate, just try and take it easy in future and use a condom.
Like I said earlier, go to the pharmacy and ask about the pill and in 3 weeks time buy three pregnancy tests if you're still worried :) good luck man, I hope it turns out alright.