So my friend has had the birth control bar in her arm for years. It’s towards the end of her needing to get it out (expiring), and randomly last month she gets a 7-8 day period. Which, she hasn’t had the entire time of having the bar birth control. Now, this month around the time when she would get a period, she has very light pink blood just when wiping, for about 3 days now. She is not using any other protection.

My question is, could this be implantation bleeding?