boyfriend responsibility problems! help

My boyfriend and I are expecting our sweet girl Jan 31. We are very excited. We both work at restaurants so when I take off, he'll be the one to make money to pay bills. It's getting closer and I've already slacked off from working so much but he still goes out drinking and spending money. Money that we should be saving so it isn't so hard on him. I say I need new shoes or pants and he always comes back with we don't really have the money and you're about to have to quit working. People I've talked to says he'll change once she is here and he holds her but I'm not sure. Is anyone else having to deal with this? He can do what he wants now because when I'm off I wot. Be making money and he will so he says this is the only time he can go out and relax and hang out. I couldn't tell you the last time I actually did something for myself or hung out with my friends. My life has changed drastically and he still gets to keep his lifestyle. What do I do? Do I wait until she comes? Or do I give him an ultimatum right now? Helpppppp!