Pimple or boil?

Zulema

My 18 month old got what seems to be a boil in between her butt and she has a Dr appt Wednesday however when I changed her diaper earlier it had blood and it freaked me out! The boil popped and has been oozing out blood. She doesnt cry or anything so must not bother her. Has this ever happen to any of your little ones and know what may have caused it?