same here. I got an email stating that contract should be mailed out around April 1st. In preparation, they suggested getting together items like social security card and immunization records. No worries!
I have received my contract and paperwork. I wouldn't worry about it if you haven't though, since I know that many of my classmates haven't either. You probably should have at least received some sort of contact from your program by now though, so if you haven't heard from them at all since match day, I'd definitely at least send an e-mail to the PD asking him or her what's going on.