5th period since Oct

I’m wondering what has changed:

I’m 29 and have a copper IUD; no hormone therapies. I’ve had regular cycles for years, until recently.

I just started my fifth period since mid October- basically one week on and no more than 10 days off before I start again.

Period symptoms are normal. Doctor checked thyroid issues and pregnancy- both negative. Is it normal to experience this as a symptom of hormone changes around 30? I’ve had no children and am far from menopause…

And ideas, I’d love to hear them. Can’t get to the gyno till February.