Was I molested or raped?

it may sound a little paranoid but it's really eats me out in these days,the last time I stayed at my friend's home,the next day my private areas were a bit burning and something like skin chaffing,I was in my menstrual period I'm used to use menstrual pads in this period,I didn't drink alcohol or something,could I have been passed out and raped?or is it about my menstrual pads,any ideas?