Super confused

Tearney • 17 years old getting married in April
Glow says I skipped a period but I don't see any period days that were skipped so I'm super confused and there are no other period days shown on my calendar what is going on? My last period was on my 1st and 2nd cycle day but idk how long my cycles are and when I was on bc my periods we irregular and I never kept track of them