Getting accidentally “sabotaged” on keto

The other day I ordered a diet coke and it came out regular, I quickly corrected it after a sip. Today I ordered a starbucks drink with sugar free vanilla. I’ll be damned if I don’t think its regular vanilla. Man it would really suck to get kicked out of keto.

Is there any surefire way to know if I am still in ketosis with a blood glucose monitor? I cannot check my ketones. Or should I just forget about it and move on?