Accidentally ate meat

Saige
I'm a vegetarian and have been for months now. On New Year's <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> my brother was eating pizza and told me it was cheese pizza. I took a bite of it and afterward his friend told me that it actually had Canadian bacon in it. Of course I didn't want to eat meat and I was tricked. Does this mean I'm not a vegetarian, I've only been a vegetarian for a few days or does nothing change?