Just yesterday I was at a friends birthday celebration I was standing in the kitchen.  The room was a little full and all of a sudden I started to feel hot and nauseated then I got light headed and dizzy.  I had to leave the room and go sit down before it would stop I thought I would pass out.  Then after a few minutes I got this unbearable headache.  i just thought this was weird this is my second pregnancy and I am 5 month (17 weeks) today.  Has anyone else experienced this?