Starting hormonal birth control during menstruation is considered safe, but doing so usually does not stop the ongoing period immediately. Instead, bleeding patterns typically change gradually over several weeks or months, and the body may take time to adjust to the new hormone levels.
It is very common to experience irregular spotting or bleeding during the first few months of use, even if the medication is intended to suppress menstruation. This unscheduled bleeding is generally benign and tends to decrease as the body adapts to the medication.
The timing of initiation affects when pregnancy protection begins; if the method is started within the first five days of menstrual bleeding, it typically provides immediate protection without the need for a backup method. However, if it is started more than five days after the period begins, a backup barrier method is necessary for seven days to ensure prevention.
A gynecologist should always be consulted to determine the most appropriate contraceptive method and to manage any persistent or heavy bleeding. It is important not to self-medicate or abruptly stop the medication without professional advice, and condoms should be used to protect against sexually transmitted infections.