Am I having symptoms?

Im not supposed to get AF until Wednesday, but I have started spotting today. My periods have always been extremely constant before, during and after being on the pill. I've only been off the pill for 3 months but it has stayed constant. I took a test last night and it had an extremely faint line (it may have just been how the test was made but I didn't pay attention before to know for sure), so then I took a digital clear blue test and it was negative, so I took a 3rd test of a different off brand and there were no lines at all. What do you think? Could this just be an early period? Or a pregnancy?