poop concern

My little girl will be 6 weeks on Thursday. Today  she had a gnarled poop at about 2:15 pm. It just kept going! It was really runny and almost foamy with lots of little bubbles and exploded out of her. We haven't had one of those poops since she was first born. She is exclusively BF and will be bottle fed during the day starting next week. After that poop I got one that was mucousy and looked like it had a tinge of blood in it. Then I got another gnarly one. I will add photos. My sister thinks it's a dairy allergy. I want talks input. I will call the doctor in the morning unless it gets worse. She isn't acting unhappy or in pain.