First Mow, New Turf

hi, I need some advice and everything I read seems to give slightly different opinions. 

10 days ago I laid some new turf. About 80m2 of it after spending days pulling up, screening and levelling my very poor back garden (I am quite proud I did it all myself ).

I read up and read up on the process and felt confident I got it right. It's been a week and half and the grass is still green and alive - so that is the first win I take

I have read that you need to mow when it grows 25-50mm (take off 25% of the leaf). However I have also read that you shouldn't stand on it for 2-3 weeks. 

Here is my dilemma, the grass stood up and grew really quickly. in some patches, its probably grown more than 50mm. Saying some, it's feels like 70-75% has grown well. I have tested a couple of patches by pulling them up and they dont really budge. So it's rooted - I think. 

Do I mow it? Or do I still leave it another week and if it grows more, it won't hurt. I have walked on it and were my wife says we sink into the turf, I think thats just us not being used to having a garden that is soft - unlike the rough tundra it was before

Thanks