Never ending ITCHING???

Hey everyone
So I had sex about a week and 2-3days ago, on New Years. I took Plan B on the 2nd. Ever since then I've had like bad itching down there. Also, every time I use the bathroom in that area it feels like when you wipe too hard and like scrape yourself raw with the paper kind of. I take 2-3 showers a day so I'm not dirty, I'm actually very clean. I never switched my soap or anything so I don't think it's a reaction like that. I just need to know what's causing the itching or what might be causing it. I don't have any other symptoms or anything aside from that basically. Only other thing that could possibly be a symptom is I've had minor on and off like spotting, the brown kind like when your periods ending but I'm not on my period it had just ended on December 29th. No odor or discharge or anything.