Is this normal ?

I had sex the 16 of July (last day of my period) he finished in me I started to have brown spotting on Friday the 21st till now but rn it changes color to light pink , I also took a pregnancy test which came out to very light faint was pink dye ! I post it here n every saw it too . But the next day I take another one n comes out negative . The symptoms I have had is very dizzy , very hungry , naseous, bloating , headaches n really tired n omg some smells get me naseous . I have also notice that my moods towards my partner change like sometimes I hate him n he annoys me n sometimes I'm so sensitive n i need him so , basically I'm asking y was I spotting from the 21till now it just changed to light pink