Pets and pregnancy

I'm only 7 dpo but the past couple of days my cat has been attacking me out of nowhere. I'll be sitting on the couch watching tv and he will climb onto my chest and lunge at my neck. He has always been very active and loves to play but has never behaved like this before. I've heard of pets behaving differently when their owners become pregnant. Has this type of thing happened to anyone else. It's too early for me to test so I'm not sure is I am pregnant but here's hoping :)