I received an email stating there was a new sign-in to my account

We want to help keep your account secure, so we email you whenever there is a new sign-in to your Netflix account from a new device. The location of the sign-in may not be an exact match to your current location because it is based on the IP address your device is using, and the time displayed is the local time of the new sign-in.

If you don't recognize this sign-in, we recommend that you change your password immediately. To change your password, you can send yourself a password reset email or text (SMS) message.

Refer to How to keep your account secure for more tips to keep your information safe.