You are not alone Sarah.
I Didn't really have anything out of the usual other than eating ginger to over come the ms with pregnancy number 1 but with this one - olives - i am eating olives by the handful and i would pick them out of meals before.

I think that it is most likely that Carrie is correct , the food we are eating that we normally avoid (bacon, olives) must have something that the body needs .
Apparently olives are good nutritional source of vitamin e and bacon a good source of iron.
Thought - Might try taking vitamin e and see if the urge to have olives dies.