Abnormal Periods

I very rarely ever post on here, but I am coming with a concern that I have. I am almost 20, and my periods have never been very irregular. However over the past couple months, my period has been very irregular to the point where i didn’t know if it was normal. This month, my period was 20 days late. I usually get it around the 7th, give or take a few days, and I just got it today. Two months ago I completely missed my period. I’m not sexually active, my diet and stress levels are pretty normal, I just don’t get it. If anyone could tell me about similar experience or what has helped you, please tell me in the comments. 💓