Does a Pokemon get it's mega stats the turn after it mega-evolves?

Question

Because my gengar is slow the turn it mega evolves, but faster the turn after.

Answer 1

Yes it does, only the speed stats lag, but everything else turn into the stats of the mega Pokemon after mega evolving

Comments

thank you

Answer 2

Since movement order is determined before any moves are used, the Pokémon's new Speed or Ability will not affect movement order on the turn during which it Mega Evolves

Source http://bulbapedia.bulbagarden.net/wiki/Mega_Evolution

Hope I helped!