BigG is right. You should always stretch the strings. Give 'em a good steady pull, tune and repeat. When the string holds it's tune you're good to go.
You mention it's holding tune better now. Given enough time, playing and re-tuning will get the strings stretched and settled in. Stretching in the beginning accelerates the process.
"The music business is a cruel and shallow money trench, a long plastic
hallway where thieves and pimps run free, and good men die like dogs.
There's also a negative side."
--Hunter S. Thompson
Guitars: Dean Sweet Wood 00R, Martin D2R, Guild D60, Guild D35NT, Morgan Monroe M30, OS baritone Uke