Should I count it as a period or spotting?

So I got Mirena IUD back in December so I’ve had it almost 8 months. I’ve still been getting periods but they are all over the place super irregular and getting lighter. I had some bleeding starting July 1st but I don’t know if I should count it as a period since it only lasted 4 days but was so light it was only there when I wiped. That’s when I was supposed to start my last period but I’ve never had such a light period before. Didn’t know if it was because of my iud or just spotting from it.