Is it okay to have protected sex when the menstrual period has just started?
Generally speaking, "having sex" refers to engaging in sexual intercourse. It is not advisable to have sexual intercourse with a condom when menstruation has just started. The specific reasons are as follows:

When menstruation has just begun, the female uterine lining has already started to shed, and the cervix is in a relatively open state. At this time, engaging in sexual activity—even with a condom—may increase the risk of bacteria entering the uterus and pelvic cavity, leading to infections and causing gynecological diseases such as vaginitis and cervicitis. In addition, the stimulation from sexual activity may intensify uterine contractions, resulting in increased bleeding or prolonged menstrual periods, causing discomfort to the female. Therefore, sexual intercourse should not be performed at this time.
In daily life, to protect women's health, sexual intercourse should be avoided during menstruation, even if the bleeding is minimal or a condom is used, to reduce the risk of infection and physical discomfort.