Unfortunately VMR, I think it could be caused by many different "things". Sorry sweetie,
. I know this is hard on you, please listen to your own self. What I mean is that, even if it only has been 3days, it's not worth the worry, stress and anguish. If "it" worries you, please, make an easy appointment with your family doctor, or a walk in sexual clinic might be able to help if doc's not an option.
Personaly, i'm a very stubborn person, i'd wait. BUT, my stubborness, my waiting to see the "doc" about my own "down there", a simple pap smear I avoided for over a decade lead me to be treated for severe dysplasia. No big deal, but, the point is, I could of avoided lots of worries if I would of simply "got it checked out".
"It's easier to prevent than try to fix".
The earlier it's "caught", the easier it is to "fix".
Listen to your body.
With love, hoping you are feeling better.
Chances are, could be nothing "really wrong", but, you are the only one who knows your body. Right?
sorry, i'm not much help)
Nice hot bath I think is in order. No soap sudds added/no crystals/no fancy nothing, plain water in the tub. Don't "douche".
As far as the lenght of your last period-sounds ok to me. I've personaly had periods that lasted anywhere between 4-9 days. Although i'm not on birth control pills.
Hoping this helps you.