Cycle question

BeautyMommy • I love my family
I'm curious as to what's the largest amount of days (regularly) that you can have in your cycle? I just started charting my periods and am on my 31st cycle day with no period symptoms. If I go by what glow says I'm 3 days late. It's possible that I could be pregnant, I haven't tested yet. But I'm thinking maybe my cycles are longer then I expected them to be.