Period?

Today is the first day of my period. Do you think this could be implantation bleeding or the start of my period?

Had sex while still on my last period (the end) and last week.

Find it weird that it’s small and kind of brown ish in color. Usually would be pink ish and more would come on as i wipe throughout the day but this time it’s relatively nothing.

Should i wait a few days to see what my body does?