Hope you ordered sprockets too. If not you'll be buying another chain sooner than you want.

 

but of course

 

If theres ANY uncertainty- just bite the bullet and replace it!!
its a cheap fix compared to crash repair , new helmet - new head?
regular chain replacement BEFORE it SHOWS stretch will prevent wearing away the spacing on the sprockets which are much more expensive.
by the time it displays "stretch", its had to grind away the sides of your cog teeth to make room for its longer link "spacing"(pin-pin) .

Im new to motorbikes but ive got 10 yrs exp as a bicycle shop mech.-
The wear or "stretch" on a chain is the play that comes when the pin and the tube hole it goes through (and the tube that actually contacts the teeth) grind away at eachother. ive seen chains where the inner plates are actually pierced by the centre tube and its fixed in place to them, that wouldnt spin unless it was really broke. but most chains should use that center tube as the bushing it should be and let in roll easily(but not loose or rattly) into and out of the valleys between the teeth of yer cogs as they rotate.
moveable, smooth but snug -probably good.
rattle- wiggle room - twist or side to side play - not good.

ps. when i raced track bicycles i replaced my chain 2-3 times a year.
30-40$ each .
because its cheaper than any of the cogs/sprockets youll wear out.
sorry for the long winded post- this partikilar subject is one of my pet mechanical crusades.i tent to overdu my convincing a bit.
but after losing my first bike to a chainsnap crash trying to wheelie, and going over the bars to break my new carbon helmet , i decided chains are the cheapest way to go, helmets 2nd, surgery dead last.