Sudden light periods while on pill?

I've been taking the same BC pill for over a year now, at the beginning bleeding was abit unsettled and random but after a couple of months it settled down into a normal, predictable pattern. But the last couple of breaks, I have bled very, very lightly for 1-2 days during the break as opposed to the normal flow for 5 days. I have taken the pills all correctly and have not been taking any other medication so is this something I should worry about?