late period

Hey guys. I have 3 different period tracking apps. One says I'm 4 days late, one says 2 days late and this one says 1 day late. I had my IUD taken out on Oct 31st and my doc said if I don't start to take a test. Well I've taken 4 and they have all been negative and there is no sign of my period. The period tracker that says I'm 4 days late is normally spot on about predicting my period. And I'm never late unless I'm pregnant. This would be my third child if I am. I've had a few symptoms of being pregnant. Any tips or suggestions?