late & 100% not pregnant, help this is strange!

So my period is now 18 days late and from the last 6 months has arrived anywhere from a week to a few days earlier to on time so usually isn't late. And there is 100% no chance I'm pregnant as I have no had sex in the past 12 months. Should a go to a doctor or is this normal?

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors