Schools will typically contact you once they receive your application. I know that some people on this forum have reported not hearing anything from there schools for 3-6 months after there application was submitted. It may depend on each school's admissions process. It does not hurt to be proactive in order to make sure that a school has received your stuff. I also know that it depends on if the school has rolling admissions or not. Those schools tend to have later application deadlines. If you don't hear back from your other schools in what you consider a reasonable time, then shoot them a little friendly email asking whether they have your info or not.