It is quite common for breast milk supply to dip slightly during your menstrual cycle due to hormonal changes. Many mothers experience this fussiness in their baby during the days leading up to or during their period. To support your supply, continue nursing on demand, stay hydrated, and ensure you are getting adequate rest. This dip is usually temporary and will naturally stabilize once your hormones balance out; avoid stress, as your supply will typically return to normal within a few days.