I remember getting this, but maybe only 5 minutes after the shower? I had quite a few moments where I was VERY VERY close to fainting, not all after the shower though so I didn't think the shower was the sole cause, but merely one of the various things that made me feel a bit dodgy. I mentioned it to my ob but all the things they test routinely were fine (iron/sugar levels, blood pressure) so we never found a cause - I was just unlucky? Anyway it is worth getting it checked out just to be sure.