Period late

According to my day app my period was meant to start on Saturday and according to the <a href="">glow app</a> was meant to start Today 
anyway I just changed my period to Being late and now glow has said my period is to be this Wednesday.
Yesterday I had one instance of light pink blood and today small amounts of lite brown blood and very mild cramps
I will see if my period starts in the next few days...
Thanks :)