How does breastfeeding affect my menstrual cycle, and will it affect breastfeeding?
Great question! The answer to both of these questions is "maybe."
No Menstrual Cycle
Every woman's body is different. Many mothers who are fully breastfeeding don't get their period for several months after delivery. Your period might not start until six or more months postpartum. Your period may start when you return to work, start solid foods, or wean your baby from breastfeeding. Even then, your period might not be regular. Talk with your doctor about this if you have questions.
Menstrual Cycle is Back
This, too, seems to affect moms differently. Some moms notice a temporary dip in milk supply at a certain point in their cycle. Most of the time, simply watching baby's cues and allowing them to breastfeed more often, if needed, is all that is required. If baby gets frustrated due to your milk flow being slower than normal, breast compressions and massage will help get your milk flowing. You can ask your doctor about using a supplement of calcium and magnesium during part of your cycle to help if you are producing less milk. If you are concerned about a drastic decrease, consider tracking wet and dirty diapers to make sure baby is getting enough to eat. Thankfully, this dip in your milk supply is temporary and should return to normal.
The makeup and taste of your breast milk can vary slightly during your menstrual cycle. Chloride and sodium levels increase, and lactose levels go down. This can result in the milk tasting less sweet than usual.
Some moms report that breastfeeding is a little uncomfortable during their period. This is due to hormonal changes occurring and is also only temporary.
SOURCE:
https://www.bellybelly.com.au/breastfeeding/your-menstrual-cycle-and-breastfeeding-5-facts/
https://www.llli.org/breastfeeding-info/menstruation/
https://www.motherlove.com/blogs/all/how-the-return-of-your-menstrual-cycle-affects-your-milk-supply