How do you know you are getting your period on the IUD?

Hi! I just got the IUD on the 20th of January and have been spotting non stop. It's gotten heavier, then slowly lighter. Sometimes when I do spot (which is mostly afternoon to night) it looks similar to a period with it being very red and little blood clots, but I know that it isn't one because it slows down and eventually stops. My period is supposed to come around the 8th of this month, but I'm wondering will there even be a difference between the period and spotting?