According to Google Play, when you sign up for a 3-day trial, you may get charged within the last 24 hours of your trial period.

Here's the exact statement from Google Play's website: " At the end of your trial period, the first billing period begins and you automatically get charged the amount in your subscriptions terms. To avoid charges, cancel the subscription before the trial period expires. "

The payment processes on Google Play are exclusively managed by Google. If you encounter any issues in this regard, please reach out to Google for assistance.