Hmmm...I tried looking up things on the web and found zippo.
Is your kitty just acting different around you or in general?
If it's in general, you may want to get her checked by a vet as sudden behavioural changes can mean that something is wrong with your kitty.
If it's just around you, then maybe you smell differently to your kitty. I don't really know, I don't know much about pregnancies. Or maybe kitty just doesn't like your new perfume, (or something similar), if you do have a new one.
Maybe someone out there can help more....though I will continue to have a look for you.