Period apps

Every one of my apps says im late. However, they all have different dates for when I should have started. So ladies, which is more accurate?

Ovia says I should have started on the 11th of January

Glow says the 4th of January it also says I ovulated around the 22-28 of December (my cycles are crazy)

And my period tracker says I should have started Jan 21st. I tested on January 7th and it was negative

No signs of af even though according to glow im now a month late