It's happened to me. If it wasn't a whole bunch of blood then its nothing to worry to much about. If it was just like strains of blood it just means you irrated your esophagus from all the throwing up your doing. That's what the hospital told me when I went for it.
Yes i did eat chilli but the blood came after all the food was out. It clearly looked like blood
Had you ate anything red the day of? Happened to my sister but she forgot she had eaten Hot Cheetos and confused it for blood.
If there was blood I would go to the emergency department...