Uncertainty about being pregnant/test

I'm currently 3 days overdue. I don't have any period cramps. All the Clearblue, Kruidvat, and Sensitest tests show negative. But the Predictor test from 12.5 hours shows a positive result with a faint line, indicating I might be pregnant. My menstrual cycle is consistently 28 days, and I've never been late. I'm worried because I'm 3 days overdue, all tests are negative except for the early Predictor test. Is something wrong? Am I pregnant or not? Or is my hCG hormone level too low?