Why would I be spotting and have light bleeding 12 days before my period?

My husband and I both are wanting kids and yet the last time we were sexually active was March 17 and we haven’t been sexually intimate lately with each other. I’ve been on birth control and now using the birth control patches and yet Wednesday and even yesterday I was spotting with light bleeding.

I’m not even supposed to be off my patch yet and all of this is happening with the patch cause my period isn’t even due to come yet, so could it be possible to be pregnant and not even knowing that I am?

My period isn’t due until after the 22 of this month and yet I just don’t understand it at all.