Your 12.5% bleach is just fine.

It was late when you added bleach so you may have not had time but when you are trying to determine if you have a chlorine demand, we like to be able to measure overnight chlorine loss. The best way to do this is to add chlorine when the sun is off the pool in the evening. Then, a couple hours later test so you'll have FC and CC numbers to compare with the next morning's readings which should be taken within an hour of sunrise.