Period is late, brown spotting and negative test

Hey ladies, was hoping for some feedback. My period is usually like clock work, every 28 days with give or take a day. I’m currently a week late but have been getting brown spotting very randomly and super light. I’ve taken a few tests and they’ve all been negative.

Has anyone gone through this? I don’t want to keep taking tests and wasting money, I’ve never missed a period before or been this late ever so I’m super confused.

I’m also wondering if it’s something I should reach out to my OBGYN about? Like I said, I’ve never experienced this before and it’s super unusual for me.