I tested again this morning and nothing

I used one of the first response tests which are supposed to be accurate up to 4 days before the missed period. Today was 3 days before so I'm starting to think this month is a lost cause
I dont get it! I have so many symptoms. Sore swollen breasts, super tired all the time, breakouts all over, nausea, and brown spotting which I thought was implantation bleeding. These are all very not normal things for me! My cycles are like clockwork and I never have spotting in between! My breasts are never sore until about 3 days before my period and the other symptoms aren't normal either!
Since I have all these symptoms wouldn't I be getting BFP? Is it even possible to have these symptoms (especially the spotting, that CANT be in my head) and then get a BFN? I know it's still 3 days before my period is due but I cant help thinking that I've failed this month

How is it even possible for me to have symptoms like this and not get a BFP? Doesn't the embryo start giving off the pregnancy hormone right after it implants? (which I think was a few days ago, given the implantation bleeding, atleast I thought that's what it was) I just dont understand
