Plan b!

So my so & i had sex on the 15 of October & he came in me so I had to take a plan b pill. I had already had my period from the 6th through the 11th of October but after the pill I got my period again from the 22nd & its still going on now November 1st. It's been more than a week & its so annoying because I've been on it for so long my periods are normally never this long. I get plan b pills can change up your cycle but is this normal? Please help ladies!