I don't know if you should be worried. I contacted and spoke with research professors at several schools, and I haven't received any acceptances yet. I also don't know if it's too late. My attempt to contact some researchers, at a school which I hadn't and much previous interaction, resulted in an expedited "rejection" email.
I think the main things (grades, GREs, LORs, research, and your personal statement) will be what makes or breaks us all. The interaction with profs might help a little, but probably won't be a deciding factor.