is it normal to just skip a month?

so i'm 12 days late and i'm looking back at my other periods and sometimes i just skip a month. i've never had sex and i am not on the pill. the farthest i've gone is oral, but neither of us were close to cumming because it wasn't for long and we had somewhere to be. so, would i be pregnant? or is it just late because i am stressing. no mean comments please. i'm on the verge of an anxiety attack.