so I downloaded a new period tracker app and my old period tracker says I have 5 days till i start…

so I downloaded a new period tracker app and my old period tracker says I have 5 days till i start my period and my new one says I'm 4 days late, I don't know which one to believe but I'm having pregnancy symptoms and I've took 2 pregnancy test and they both said negative. I don't know what to do.