my baby is 3 months and one week old and hasnt had breastmilk since he was about 2 weeks old. Ive relactated this past week and am up to about an ounce a day, but since ive been giving it to him hes went from very rarely spitting up to spitting up a few times a day. Could it be my breastmilk? Whats the best way to reintroduce him to it? Any help would be appreciated since i want to give him my milk but dont want to give him an upset tummy bc of it.