Not sure whether to test or not

Cassie • 🎉🎃🍁🍂 blessed with a beautiful 3 year old boy a 2 year girl and a 9 week girl👨‍👩‍👧‍👦

OK its been 5 months post partum, I went on the Depo jab the day I left hospital 7/10/16 I've had my after pregnancy bleed that lasted 8 weeks, since then I have had periods lasting anything from 4 days to a week, I had a week period last month and my tracker says I'm late by 4 days of my current period, should I do a pregnancy test just to be sure or wait a little longer,

This is my current chart status for my periods.