Can water (about a gallon) on carpet for 3 days in summer cause mold?

I had a jug of water (about a gallon) spill onto my carpet three days ago. I noticed this only today -- i used a shop vac to suck up the water today and kind of dried it out with a hair dryer. Its still a little damp. Its been warm the last few days -- Is it possible that i will have a mold problem? Any suggestions about what needs to be done?