Peeiod Changes

OK so I'm not on any BC and I'm sexually active only with my husband of 5 years but anyway last month and this month my period has been very light... For example on a normal period I would have to change my pad or tampon at least 3 times a day but the last two months I could have worn the same pad the whole 4 days(even though I didn't) it was just that light. It was to much for a panty liner and not enough for a pad or tampon...

Anyone experience this if so what was wrong?