Spotting

Hi ladies so I've been on the pill for over a year, this last month I've forgotten it a few times but doubled up the next day as I'm supposed to just to make sure everything adds up, but my period was due on Saturday the 9th of April, it usually comes the night before (8th of April Friday) it's now Monday the 11th of April and AF hasn't appeared, but I had spotting on the day of expected period (Saturday), and the day after expected period(sunday) but none on the 3rd day (monday) , has this happened to anyone else? Me and my partner are happy but nervous incase I could be pregnant :) we are not trying at the moment as life is very busy right now, but I'm going to do a pregnancy test tomorrow if AF doesn't show today!