My stool has been black for a couple of days, no bleeding only black stool, should i be concerned?

If it is black and tarry then you need to be checked out. Bleeding from the upper intestine can cause black tarry stools. It probably just represents what you have eaten and unlikely to be from intestinal bleeding unless you have been taking alot of non-steroidal anti-inflammatory drugs like advil. Would monitor and if it continues see your PCP for further evaluation and treatment.

Black stool can be due bleeding in upper part of intestine. It would be prudent to see a doctor and have your stool tested for occult blood.