" I can't tell from the pictures if I have Nutsedge or not. I will
wait
until I get a seedhead and take it to my nursery. "

You may be waiting a long time. Nutsedge is a tuber, so it doesn't
produce a seed head. One way to identify nutsedge is by when it
grows. It only becomes a problem when it's hot and there is a lot of
water present. Then when you mow the lawn, a couple days later you
will see blades sticking up a lot higher than the grass.