light pink discharge

So I was supposed to get my period this week. But instead of my normal flow I have this weird pink discharge. Nothing that's even noticeable. And it went away after and I haven't noticed it come back yet. Is my period late? Or was that my period? I've been hanging around my friend almost every day for a month or two. We work together, work out together, go out, etc. Anyways she had the same problem last month or the month before. Are our cycles just syncing? Is that even an actual thing?