Telephone Technical Support for new MacBook Pro

That is the explanation. Apple starts the warranty period when the product is shipped to the reseller, so it has been there for more than 90 days. It will be easy: you need to contact Apple, explain the situation, and ask if they want you to send them a copy of your purchase receipt. The warranty period will then be adjusted to your actual purchase date.

I would just call Apple phone support and ask them that question—

Under the original warranty you get 90 days of phone suppport

Apple Complimentary Support

Get phone support for a device that’s out of warranty - Apple Support

Holds true in the USA, Private, second or third party sellers will have there own policies and own in country coverage.

Where and when did you buy it?