Implantation bleeding?

So this morning when I wiped I had a pinkish discharge like a small amount of water light coloured blood, Google directed me to implantation bleeding but I'm on the pill? I've been on the pill for years and have never had this happen or had spotting of any kind. In the past two weeks I have become sexually active not using any other protection, just relying on my pill. Anyone have any idea what this kind of discharge/bleeding could be ?