Bleeding cycle day 18!!!?

Has anyone else ever had this happened before? I woke up to use the bathroom yesterday morning wiped and seen blood it freaked me out because it wasn’t just a little it was like the beginning of a period or something! As the day went on it turned brown and very small amount and was pretty much nothing except tiny brown specs by the end of the day.

We’ve been TTC almost 2 years now. And my periods have always been very regular and this has never happened before. Today there is nothing at all does anyone have any insight on what this could be ?

Thanks for reading ❤️❤️❤️