What Causes Irregular Menstruation With Dry Patches Near Vagina Post Birth Control Pills?

I recently stated birth control on feb 6th 2015 and it is now March 3 still on my period but I felt like I was getting a rash because of wearing a pad all day but when I checked myself it was like dry scabby patches on Botha side of my vagina. What is this? And what should I do????