Pregnancy symptoms just in my head?

Okay so I know the saying that if you think about being pregnant your body will respond like you are. I may just be losing it but I don't think I've been thinking about it and have seemed to be put off of my favorite food. I can't eat it and the smell makes me nauseated. I have been moody and normally my periods do not make me moody.. but it could always happen. My period was very light at first and maybe medium now for 1 day. It's confusing and maybe there is hope that I am pregnant. I have not taken a test we haven't made a trip to the store. I am bleeding maybe on my period just enough to need some protection. Any help?