Re: any one have those days when ....
Your daughter is only a 3 year old, it is natural for her to want your undivided attention and when she does not get it she will keep on and on. She does not realize you have other things on your mind.
Try to make special time with your daughter, love, cuddle her and see if it will make a difference. Take afternoon naps with her or whatever to be close to her. She will have your attention and you will get a little rest.
She is noticing that something is not like it use to be, maybe you are focusing a lot of time on your pregnancy and she feels left out.
Work on connection and bonding with your 3 year old, it will pay off down the road, otherwise she will become a demanding child on into her teens and later.
Age 3 is a precious age.
Mother of 5