Plan B pill

So I had sex on July 21st the day my period ended and took plan B a while after bc we didn't use a condom but he didn't ejaculage so we just wanted to be sure and then 7 days later I had small spotting for 3 days and that was it, is that supposed to count as the next time I receive my period? Because I was supposed to start on the 14th and I'm 7 days late now , I also took a pregnancy test and it came out negative I'm just really worried sorry... Please help and no hate comments please I'm just worried