Is my period late?

So I have another period tracking app that I have been using for 3-4 years now before I found Glow. The last two months my periods have been out of wack. Two months ago it was 4 days early. Last month it was 9 days late. Now my other period tracker says I'm 2 days late and Glow says I have 2 more days. I have had very regular periods my whole life until the last 3 months. I became sexually active 6 months ago. What does this mean? Should I test or is my period just crazy all of a sudden?