hey KAM welcome to the site
I dunno bout your #'s 1+2, but #3 chains will 'stretch' with use, this is normal with a new chain as all the little parts are settling into place. You may need to take another link or two out before it is fully settled but give it some time by using the tensioner to increase tension. Some people just use the tensioner but I don't like the look and plan on having proper tension in my chain without a need for a tensioner. thats just my personal preference ymmv
good luck with your ride and I'm sure one of the more experienced folks will be around soon enough