Yes, do not confuse with bleeding bleeding, because after any surgical intervention, however small is, You should always have a small bleeding that will give way to the formation of a clot that is going to form new gum in the extraction site.
Depending on the type of intervention that has been made, such bleeding is higher or lower and will last more or less time. The loss of blood soaked gauze, to spot a pillow or spitting, They are normal. If blood volume is larger and fills his mouth in a few seconds, then if it can be bleeding and should immediately consult your dentist who made him the intervention.