Desperate for help! Please

Ashleigh • Engaged to my best friend and soldier. We have a 5 year old son, and currently ttc our second ❤️
I'm 23 years old. I have a five year old son from a previous relationship. My fiance and I have been trying to get pregnant for almost six months. I've gone from a 28 day cycle Feb-April, and my last period was from May 28-June 1. I took a pregnancy test and I got a BFN :( That period was a lot lighter than usual. Glow says my next period is due July 16th. I'm very crampy, nauseated and tired all of the time. I'm constantly wanting to take an afternoon nap. Should I wait until glow says my next cycle is, or should I take a pregnancy test? Any advice would be great. Thank you, and baby dust to you all ✨