Best time to test?! Best kind of test?

I kind of had the same thing happen. I was supposedly late by Glow but I was irregular. And when my period was "late" a week, I tested and nothing. Well, long story short, I was over a month late by Glow and finally Feb. 1,2016 I got my positive. Glow is good for those who are pretty regular. But sadly for those who aren't or experience something that throws their body out of wack, it won't have a proper answer. You know your body best. If I were you, I ld wait until a week after your period was supposed to be due and then try. That's what I had to do, and trust me when I say, the waiting sucked, but I got my positive. I hope this helps!