Is it possible conventional pregnancy tests don't work?

Viola
I'm 5 days late, but the test is saying I'm not pregnant. My period is very uniform, and has been on the 1st of the month for at least a year now. I did account for February being a shorter month, and I know there can be other causes, but this has me wondering if there have been cases where the pregnancy tests just don't pick up some pregnancies?

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