Brown blood

I’m confused I usually start my period around the days 27-30, it only lasts 3-4 days with horrible cramps. However last month nothing would come out. I would only see blood when I would wipe which was usually brown blood & sometimes a mixture of normal blood (red). But my question is was that my period?? Was my vagina just cleaning itself or was it implantation spotting? but I’m sure I’m not pregnant.