Hi, my doctor recently changed my birth control brand which caused me to start my period a week early. I have now been on my period for a week and a half. Now the outside of my vagina is really chapped and sore. I thought maybe its because I have been having to use pads for a longer period of time, and its just rubbing it raw. I am in college and have to walk a lot so I thought that was the cause. Is this normal?