throwing up black stuff

i don’t know if this is the sub for this but i recently stopped birth control . and my last time having sex was january 1st . well my period came on and this would’ve been my last day . i felt sick all day . took a nap and ate . (TMI )i woke up and threw up some type of black substance with food in it .Sorry yall the black stuff was oreos .. i’m not bleeding 😭 but idk why i’m throwing up. now i’m scared . any advice ?