After getting pregnant, should you go to the gynecology department or the obstetrics department to set up a medical record at the hospital?

Patient's question:

Last menstrual period was on May 20th, menstrual cycle is 30 days, and the period lasts for 7 days. Can I go to the hospital to register now? Should I go to the gynecology department or the obstetrics department? Thank you.
First follow-up question: The maternal and child health hospital here is also divided into gynecology and obstetrics departments.

Doctor's answer:

It is necessary to consult the relevant department at the hospital to apply for the card promptly. The specific time is usually determined by consulting the hospital, and there are no specific requirements.