I have never had any kind of animal allergy my entire life. I live on a farm, two dogs, two cats (barn cats though) sheep, chickens... lots of smells, animal dander, the whole bit.
Before I got my BFP (I was actually only about 7 or so DPO) I was at my father in law's house, playing with his super attention-y cat. I got in the car and my eyes itched and burned for about 45 minutes. BAD. Swollen, red, the whole deal.
We jokingly said that maybe I was pregnant and the baby was making me allergic to cats. We were 100 percent joking. (we'd been trying for years) After I got my BFP I Googled it. Turns out it's not terribly uncommon. Who knew????
I haven't had an issue since, but MAN was it weird.