Pork.
When I was pregnant with DS2, my DH suspected that I might be pregnant before I tested due to the fact that we went out for dinner at our local RSL and I turned to him and told him I wanted the pork ribs for dinner. The look he gave me was priceless. I hate pork and I especially hate ribs... gross!
Oh and pork crackling. I actually used to get grossed out over people eating it and would tell them so. But when pregnant with DS2 I craved it like crazy. I can't eat any of the above things since having him though.