I have been accepted at 1 of the 5 universities that I applied to with an assistantship offer. However, I am waiting for a response from the other 4 universities, and I don't want the one that accepted me waiting because I fear that I will lose my spot or not have an assigned advisor. I have not contacted the university at all since I did not want to make any promises before officially accepting their offer. Should I contact them? and should I worry about losing my spot or not being assigned an advisor?