two questions if anyone can help

Xochitl
My period is now late 8 days. Each time I enter "my period is late" into the app it just moves it by two days down. I was suppose to get my period may 20th and still nothing. I took pregnancy test 4 and 2 days ago. Both times negative. First question, will this app just continue moving my period two days down continuously? Second question, did I take the test too early?