I use to go through that but I thought it was normal I never thought it was because of stress, but if that's what the Dr says then, that's probably why.. All females are different some have their period for 3 days 4, 5, 6, or 7. And I'm like yourself I have it for 5 or 7 regular and if I eat stuff like hot sauce, lemons, limes, orange juice when I'm on my period, it makes my period last longer..