Testicle Regrowth, 90 Days Test.

[jrvswim]

I had my varicocele surgery on March 4th. I am 21 years old with low test. My Uro said he expects my testosterone to increase in around 90 days after the surgery. Why 90 days. Would the increase be gradual or heavily weighted towards the end? I am pretty young, could I expect my left testicle (the one with the varicocele) to regrow, or am I too old for this? If it could regrow how long does it take?
Thanks