abnormally heavy flow

Okay, so i've been having an ABNORMALLY heavy flow. I'm sure it's not as bad as I'm making it sound but usually on my period I can get away with using a regular sized tampon for ~6 or 7 hours before changing it and I never leak. However, the past two days I've had a very heavy flow where I've leaked through tampons after a few hours. Some may suggest using a larger size tampon but this is so unordinary for me. Is there anyone who may be able to help?