Spotting? 🍎

Hey, my wife and I haven’t started trying yet but I had a weird question. So I’m 26 and my periods are always very regular, around the 20th of each month. In December (the 21st) I had a one day period (usually 4-5 days like clockwork). It’s never happened before and it threw me off. It was very heavy and I put it down to stress from the holidays. Today I’m having very light bleeding- started about an hour ago.

Are my periods just all mixed up, could this be the start of my /actual/ period incredibly early? Or is this something that could be more serious. It’s very light blood, was there today three times when I wiped. Not very much but it’s there and this a total first for me.

There is no chance of being pregnant yet, so it can’t be implantation bleeding or whatnot. Any advice?