I've done this a few times already some people may not have had the idea...

MOST of the Top 10 Credit Monitoring services offer 1-week to 1-month trials for free or $1.

The thing with trials is they are usually a pain to cancel/take up time/annoying so we never do them....

Create a virtual card number (I can do this online with Citi Visa Credit Card), use virtual number for initial trial registration, cancel virtual card number few hours later or after you view your credit score/report.