Should I see the doctor?

I don't know if it's because I've been exercising or just because I'm slightly deranged but I've been having one of the oddest food cravings possible. I've been going to Jazzercise consistently for eight weeks now and I feel a lot better, I'm not tired and I don't have a muffin top anymore. But I have not changed anything in my diet. I still eat whatever I want. I went through a brief cheeseburger and french fry craving and if the mood suits, I drink a martini or a beer. So I really can't understand this new craving. Thomas does not like it, not one bit. I keep serving it to him, meal after meal. Today when I heaped it on his lunch of flat bread and bleu cheese, he made a point to come over and stare at it. "What is this stuff?" That stuff? It's LETTUCE. I can't get enough of it. The cool, crunchy bitterness of fresh lettuce is so appealing recently. What does that mean? Chocolate cravings mean low iron, but what could a lettuce craving mean? Hopefully it means something other than severe instability.