I am just wondering is it possible to see results of hair growth much earlier than 3 or 4 months. Has that happened in some cases? And how soon has that happened?

Some hairs in grafts never fall out and, after being dormant for a couple of weeks, start to grow. I have had a few patients where nearly all of the grafts started growing immediately. I have had some that, after the hair initially fell out, the growth didn't start until after 8 months. Most are right about 3.5-4 months before anything is seen.
Pretreatment with Rogaine and postop treatment with GraftCyte have been reported to help speed the regowth but this is inconsistent. Long term results don't appear to be affected by the time of onset of the growth.