When to test?

Ashleigh • Gave birth to my first on 2/21/15. Lincoln James. 💙
Just trying to prepare myself and figure out when I will need to take a HPT
​This is my first month using glow and my first month off of the pill.
​Based on what I input, Glow is estimating AF to start April 4th. However, because I just got off birth control, I know this may not be accurate. 
​Should I test a few days after April 4th if AF hasn't come yet, even if I know there is a possibility of being late/irregular due to being off birth control?  
​I know it is not likely to happen this month, but we are actively trying anyway and I just want to have an idea of when I should test. :) 
​I'm new to this whole thing and learning as I go. Haha.