TTC 4 days late 18 DPO

Jeeneezuss

I'm currently 18 DPO and AF is 4 days late. I'm still getting BFNs on pregnancy tests. Has anyone been this late and gotten BFNs but ended up getting a BFP? I'm getting really discouraged. I was on the depo shot for 9 years, had my last injection March 16 this year and have been trying since the beginning of October. I started having a period in Sep on the 9th and also had one in Oct on the 9th. On the 6th of Nov i had light pink spotting for a few hours and have been having light cramps but they stopped yesterday also backaches but no AF. Idk if my body is still working out my cycles but it gets stressful trying to conceive.