Anyone else getting annoyed with mother in law?

I don't live with my mother in law but will be moving back there soon to help us get on our feet financially.

At the moment everything she does or says I find irritating. I feel bad for my husband as he has to listen to me nag about how annoying his mum is... Most of the time he agrees because she favours her daughter and her husband over us and it's so apparent.

But today I have found I just can't snap out of this mood I'm in... I just keep thinking of stuff she might do in the future based on stuff in the past.

Is it just me who has become a bit negative towards female in laws since being pregnant?