Sc2tog

[Lisaszk]

Am getting stuck on this line in my pattern.single crochet in 12th sts from center back, (Sc2tog) 11 times, sc in last stitch, turn (13 sts)

[NCcountrygal]

Sc in 12 stitches (from center back). Then sc2 tog 11x. Sc in last stitch.  Total should be 13 sts.  Goofy wording for sure lol

sc, sc2tog x 11, sc.  Seems what you’re suppose to do. What are you making?

[Granny Square]

I suspect there is a typo, that 12th sts shouldn't have the bolded s.  

I am guessing that you are making a top and it is asking you to perhaps shape the neck line or the armhole?    --Oops, NCcountrygal types faster than I do, I agree with what she said; some patterns give a total stitch count at the end of the row as a 'sanity check' so you can make sure your count is correct, it is not an instruction to make more stitches.