Late but negative tests?

Sydney

I’m 10 days late for my period, and I’ve taken 3 tests and they’ve all come back negative. I’m not on BC nor have I recently changed any medicines or my routine. If by the end of this week I’m still negative/ not on my period I’m going to go to the dr to see what’s up. But what I’m wondering is, has this ever happened to someone? Where you’ve been this late with negative tests? I’m kind of freaking out. No symptoms or anything either...