Pre & Post Surgery Exercise

Apologies if I am covering old ground here, I did search for the answer in previous threads but couldn't find anything.

I stopped going to the gym a week before my surgery in 3 days, but I've read a lot of information online regarding timeframes as to when it's okay to go back to the gym ranging from weeks to months. My hair is my priority as I'll have many more years to go to the gym but I'm just curious what damage can be caused?

I'm having FUE so after the initial healing what impact would going to the gym in 2 weeks cause? FUT I can 100% see why straining with weights would be an issue with the stitches!

Don't worry about the above! Finished my 2 days surgery today and I have no intentions of rushing back to the gym!