Can warm water from a shower change my Essix retainer?

I only got my retainer this afternoon, when I got home I took a shower with them in. The water was warm but not steaming hot, I somehow got a little bit of shampoo in my mouth and collected some water in my mouth to get rid of it and than spat it out after 10-15 seconds. Once I put it back on I felt like it was a little looser than usual I don't know whether I'm being paranoid or not however I would like some advice before my teeth begin to move.