‘Off’ period or implantation ?

Hello. My period comes most months on the 17th. This month it came on the 12th and lasted only 2 days. (Usually last 4-5 ish ). Stared like a normal period but wore off very quick. Had 2 days of normal/heavier and then light bleeding and yesterday was nothing but one tampon of brown spotting.

My last pregnancy I had a “period” a few days early and lasted about 2 days. I havnt taken a test just bc I’m a bit nervous. But looking for similar instances. Have any of you had something like this happen and be pregnant? And yes. I know. I won’t know unless I test. Just looking ppl who can relate I guess