Late period but negative test results

First time mum

Hi

I was due on my period 5 days ago and my period is never late! I’m always bang on time and very regular so this is really unusual.

I’ve taken pregnancy tests but they’re coming up negative. Is there a chance my HCG levels could show up late? Has anyone experienced this? I’m experiencing symptoms that I don’t usually get around my period. For example, I’m getting shooting pains from my armpits into my boobs.

I’m going to take another test in a day or two.

Thanks