HELPPP

My period is 2 weeks late.In on xuxle day 50 but I can't be pregnant because I'd never had sex .I've been getting my period since I was 12 and I'm 18 now any they are usually pretty regular.I'm on no spets of birth control either, I don't I is of it matters.I'm just so lost!I keep getting like light cramping when I'm about to sleep or just waking up or even if I'm like laying down.I also have white discharge.Some times it's thick white other times it's just watery clear liquid.Can some one tell me what's up? Please