Vinyl tiles on concrete

Hi guys, I want to lay vinyl tiles in this bathroom.

Should I be worried about the damp? We have recently had a bath removed and the shower put in.
There was no damp when I lifted the carpet.
We are in a flat on the third floor, I don't understand where its coming from.

I hate to ask another damp concrete question but when I did a search I just got more confused.

 

Thanks for the speedy reply.
Your right, I had a look underneath.
The guy is coming around tomorrow morning.