Talk to Pediatrician on Milk Protien Allergy

My 14 month old daughter exclusively mother fed till one year , does greenish mucousy stool after ingesting milk or milk products such as yougurt , her stool test was positive for occult blood but no frank blood ever seen , no respiratory or skin symptoms , no other GI symptoms such as vomiting or reflux , she has a good weight and height and good physical and mental development , my only concern is her nutrition as I cannot put milk in her cereal or other foods I'm worried about her calcium levels , she still mother feeds thrice a day but no other milk intake