Brown color in spit up?


FTM here - my son spit up some brown/red around day 3 of life and doctors said that was totally normal as my milk was still coming in and I did have some nipple trauma that could have caused some bleeding. He’s now almost 2 weeks old and last night we noticed some more brown spit up in his bassinet. I’ve attached some pictures. Should I be worried or call my doctor? Is this normal? Any advice helps! Thank you!