New to TTC.. Could use advice!

I am currently on CD36 and I am not exactly sure when AF is supposed to show because every since I got off BC 6 months ago I have been everywhere.. I've had 30, 35, and 40 day cycles.. I tested today and got a BFN with a walmart cheapie.. I used a clear blue digital two days ago and it was also BFN.. I have had some brown tinted cm for the past 3 days.. Today it stopped and I noticed I've had alot of creamy cm and a big glob of foggy with a yellowish tint EWCM today. I had pretty bad back pain last night and I actually thought it was a kidney infection but it turns out it wasn't and the pain went away.. This app says I should start on Tuesday.. I have really no signs whatsoever of AF.. I usually always get horrible cramps and body aches a couple of days before.. Also the brown tinted cm is very unusual for me.. I have never "spotted" before between cycles. Has anyone experienced this? When did you get your BFP?