Really weird period or implantation bleeding!

So confused. I’m 36 TTC for 3 months now. This “period” I had recently was not normal for me. I has very light pink discharge when I wiped once on the 21st of Nov which was 13 DPO. Then nothing it stopped until 2 days later which was 15 DPO (also the day I was expecting my period. It started of with some brown now heavy at all then processed in to light pink still nothing more than a little blood when I wiped nothing close to a normal amount for my period no real cramps very slight if anything in my lower abdomen area. I usually have stronger cramps especially the first day. Now on to 16 DPO still light flow if you could call it that and maybe the color was dark pink to a light red. After this it stopped. No PMS, not normal cramping or flow or color. Took a pregnancy on the 26th test 18 DPO it read negative. I’m going to take another tomorrow, but what do you think? Was it just a really odd period? Or implantation bleeding on the day I’m supposed to get my period?