Urgent Help!

I cut my new turf lawn today. Its well rooted down and was getting pretty long. There was no height adjuster on the mower but its not a flymo. It seems to have faired quite well although in a few places the grass is a bit sparse - not bare - just sparse. Will it thicken up ok? I am really worried ive made a terrible mistake but the guy from the turf place told me to cut it about now. Ive totally drenched it with water this evening and using some of the cuttings i have sprinkled them on top of the turf to act as a mulch type thing (ive heard this is good). Have i totally made a hash of my new lawn? Im so worried i have cos i spent so much time and effort on it.
Please help

 

Should be OK. At this time of the year it's cut and water. I cut mine three time a week when the weather's like this and I have the sprinkler on it every night.

 

Hope you are on a meter.

 

Grass is quite robust but if you find bits getting sparse, buy a small packet of grass seed and sprinkle it on before you water it.

 

Err..

You hope I'm on a meter?

Why?