How do you know when you come on your period??? I come off of mines on the 21st of March & I don't know..& I had sex the day I was coming off of mi period like the first 5 or 16 seconds we didn't use protection it was alil bit of percum?? So I'm not really sure what I'm asking but need help..cus now mi mom keep saying it's something different about me that mi face is alil bit fat now & that I got lighter so do this mean anything???