Implantation Bleeding?

Hi everyone! I started having very light bleeding & cramping on the day my period was predicted to start (Tuesday). My periods are typically very heavy & the blood is usually very red with clots. This time the blood has been light pink-ish/brown with no clots and the flow has been so much lighter than my normal periods. I’ve used a couple of light tampons but they haven’t been filled up at all when I remove them. 2 days since this started and the blood is almost gone, but I usually bleed for about 4-5 days on my normal periods. I took a digital pregnancy test on Thursday morning that was negative. Should I wait a couple more days to take another one or is this just an extremely rare light period? I’ve never had a period this light before…