I have whitish smoke coming out of my exhaust pipe?

I drive a 2002 Mitsubishi Lancer and the last 2 days I started my engine and all this smoke has been coming out of my exhaust pipe. I need to use the car and would like to see what's wrong asap and if it will cost anything. Is it safe to drive a few days like that or not? I did notice that when I tried to back down my driveway the engine sputtered a little bit so I didn't go anywhere. What is going on?