Period or spotting

So I am usually an on track girlie with her periods. They come once a month every 21 days well recently I had some blood come out and I wasn’t 100% sure if it was my period because it was too early like 11 days early or spotting because I typically don’t spot. I don’t know if I should put it down as a period or spotting because it wasn’t heavy and it was only there for 3 days, and it didn’t necessarily need a heavy pad but just a linear. So my question is should I put it down as a period or spotting??