I don't know what is going on! Plz help!

I'm so stressed out and worried that something is seriously wrong with me. I've been having regular monthly periods since going off birth control last year. Except for one incident of having to take Plan B I have had a monthly period. This time around however, I had all the usual PMS symptoms and then last week I had some cramping and spotting so I figured that period was on it's way....days pass and still except for tiny bits of spotting, nothing...nothing for days so today is day 6 of my missed period and a tiny bit of blood and then nothing! I have all the usual PMS symptoms but also extremely tired and naseous which doesn't typically occur with my period. I tested this evening and still BFN! The blood hasn't increased and the cramping is still there but I honestly thought I was pregnant . Is it possible that it's still too early? Or was all this spotting just my weird period? Does anyone have any advice for me? I honestly don't understand what's going on 😭☹️