Just a quick reminder - 2013 W-2s and other informational returns don't have to be mailed until January 31, 2014. Your employer isn't late if you haven't received your W-2 yet.
And no, you can't use your last pay stub to file your return. You can use it to estimate how your taxes will come out but you or your tax pro have to have your actual W-2 before you file the return.
And if you don't receive your W-2 in the next week, it's your responsibility to contact your employer and attempt to track it down. There are options if you don't get your W-2 but the first thing the IRS will want to know is what did you do try to get your W-2.