Help I don't know what's happening!!

Addison

Im 15 and my period is 3 weeks late but the cm is going crazy! Yesterday there was so much and it was so watery that it went through my underwear and it made my pants wet. What do I do?! Is this normal or is it bad?! Also I had a 13 day period the month before which was crazy and there was lots of blood. I am not sexually active at all either.