Period Question

Trigger warning: Weird period question... or lack of...

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Anyone experiance a similar circumstance? I have been using the period tracker app called glow for about a year. It has been reliable on predicting my period start day. However, I am randomly 9 days late. I have took 4 home pregnancy test and all say negative. I am having an unusually frequent urge to pee and now I am having mild cramps and a very slight spotting of old brown blood all day today. I am not under an unusual amount of stress or on any medication that could effect my cycle. I am not on any birth control, but I also use the app to avoid my fertil days. I am going to see my doctor later this week. Until then... anyone experience this... was it nothing or a baby?