Terrified my 3 yr ild may have lyme.

Me and my family took a trip to florida for vacation and went to some place where we all were bit by mosquitoes badly, couple days later my sons neck grew a rash , looked like a ring, the doc say he may have contracted lyme disease, i tood him it was just misquitoes that bit all of us, but he said he may have contracted it before we even went to Florida. Then he got sick and one day complained about not being able to walk, something was wrong with his legs. We are terrified rite now. The doc gave him almost three weeks of antibiotics i think. They wont wven do blood tests on a 3 yr ild for it... Will that antibiotics get rid of it if its early stages? Also here are pics of the bites. http://imgur.com/XVDaNs1 http://imgur.com/R0DjIhG http://imgur.com/ubxWIhM

Any opinions or suggestions will help .. plz