check processing time on USCIS website.
https://egov.uscis.gov/processing-times/
Form "I-129 I Petition for a nonimmigrant Worker"
Field office or Service Center "Vermont Service Center" (since this is where TN I-129 are processed)
click "+ read more" to see the bottom
as of today it says
2 Months to 4 Months, TN - North American Free Trade Agreement (NAFTA) professional,
April 06, 2020
Since yours was filed April 27th, it is still within normal processing time, since April 27 is after April 06, 2020.
We have posted a “Receipt date for a case inquiry" in the table below to show when you can inquire about your case. If your receipt date is before the “Receipt date for a case inquiry", you can submit an “outside normal processing time” service request online.