ok repost update!!!!!

That could be one day of a light period.

could be implantation bleeding. Have you taken a test yet?

that happen to me also this month for 3 days and on the 4 day boom there goes af.

i have had periods like this...
where i show nothing at all on a pad, even sometimes not so much on a tampon. the bleeding would change throughout the day.
but when i wipe there is a lot or with some little clots.
i dont know the answer but i sometimes would think that it is just because maybe the labia are close enough together that it isnt coming out.... or that it was light enough that it wasnt flowing much onto the pad... but then with gravity or with the use of the br more would come out.
sorry i know its not a great answer.... but i hope it kinda helps....

I have had quite a few issues with bleeding. I'm not a doctor but if its not a lot I dont think its anything other than spotting. I do remember spotting one time but I was told that if the blood is dark or almost brown it old blood from your last period. As long as the blood isnt bright red (meaning its fresh) its semi-normal.