3 days post op and im able to stand pretty straight.is this normal??

I'm 5"1' i just had a full tt 3 days ago and I keep reading how difficult it is for u everyone to stand up straight after weeks. Well as long as I am on a pain pill I can stand up fairly straight ( not 100%) off course, but just tbought that was odd. I was thinking maybe because I am only 5'1"?? Is there anyone else tht is able to stand up fairly straight so soon? I would love to hear about it.