Potentially TMI Paraguard Period Question

So I got my IUD almost 3 weeks ago now which was about 2 weeks after my last period. I’ve heard that it is a good idea to get the IUD during your period but not mandatory. Anyway, my period started three days ago (it was a day late which it has been for the past couple months) and was heavy the first day and practically just spotting for the next two days and now is completely gone. I have never had a period shorter than about 4 days and this one didn’t even last that long. My BF and I had sex on the second day and after that is when it started to get lighter (it actually stated to get lighter that morning). I was wondering if this has ever happened to anyone else or if I have something to worry about. I was so scared my period would be so heavy this month to the point that I packed half my box of pads in my bag before I went to school before it started. This has just been freaking me out and I know I won’t feel better until my next period (if I even get one). Has this ever happened to anyone? I could use some advice.