May be prego?

Me and my boyfriend have been trying to have a baby. I just got off birth control August 9th then had my first period on the 12th. I knew my body was gonna have to reset itself since my cycle was never regular while on the BC. I got what I thought was my period on the 5th of September and ended the 8th. it was rather short, only 4 days. Trying to use this app to figure out my cycle is kind of hard since I have never kept track ever before. A wording to the app I was supose to get my period on the 27th but am 6 days late and but have been having craps that switch sides for over a week. Should I take the test or wait to see if I get my period