Late period

I’m 17 days late. Took 2 pregnancy tests a few days ago both negative. I’m on the mirena iud for 2 years now and spotted like a week and a half ago. I have been sexually active. And was treated for chlymadia about 3 weeks ago.. I’ve had periods since I got my mirena but some days it’ll be super light for like 2 days or normal for 6 it all depends. What’s your thoughts?