@mommachick2016 I read online it says the same thing he has reflux so he throws up after evrybother feeding im breastfeeding as well...so I can agree he might be dehydrated from throwing up so much

this happened to my son after I bought him home luckily the next day he had his 1st appointment so when I showed the doctor and told her I was breastfeeding him she clearly said it was that he's slightly dehydrated and recommend me to supplement with a oz or 2 of formula but definitely call his pediatrician to ease your mind

Is he breastfeed? I've heard babies can have blood in their pee if the moms nipples bleed during feedings. Have you checked to make sure he isn't dehydrated?