Cycle length changes?

Morgan

So I got of bc in November 2019 and before/after that my periods were 28-29 days ALWAYS. The last three months since TTC my cycles have been 31-32 days which of course makes me think I’m pregnant then I’m not. Well now my app is calculating based on a 31 day cycle with today being day 31 and no period so far. Thoughts? Idk what’s up with my body and I don’t want to get my hopes up.