Craving beer while pregnant?! why is this?

So I am 11 wks pregnant and have been badly craving beer.this is my first pregnancy and before getting pregnant I absolutely HATED beer.now that I'm pregnant I'm absolutely craving it.everytime I see my husband with one it drives me crazy! Of course I'm not going to drink any.would never want to harm my baby.I'm not that way.not even one sip wud b worth risking the lufe if my unborn child so please do not think I have been drinking while pregnant or that I'm thinking of doing so definitely not the case.all I want to know is y on earth am I craving something that's a huge "no no" during pregnancy? Has anyone else experienced this?? :0