Okay this is what is going on.
We moved in our house a couple months and noticed a weird smell coming from our bathroom/walk in closet area. It is almost like a urine smell. We narrowed it down to the wall directly behind our stand up shower. My husband took out the drywall which is in our walk in closet. You can see the hot and cold water pipes coming out of the concrete slab. There is a gap between the pipe and the concrete and that is where we noticed the smell the strongest! We looked under the shower and did not see any water anywhere else. We have not seen any water leaks or damage around the shower. The drain itself in the shower can be very mildewy and musty sometimes. Where could the smell be coming from? It smells like its coming right out of that gap, but I don't know what could cause it. Concrete slab leak or something else?

Please help.