Your billing schedule anchors to the day you signed up.
Example (7-day trial): sign-up on January 5 >> trial ends January 12 >> renewals on February 9, March 9, April 6…
Because the cycle is 4 weeks rather than a calendar month, your charge date shifts slightly earlier each time.
Your exact next billing date is always shown in your account settings, and every charge comes with an email receipt showing the amount and your next date.
To avoid the next charge, cancel before your renewal date - see Canceling your subscription. Plan prices are listed in Plans, pricing, and renewal.