I'm breastfeeding, so why have my periods started again?

Breastfeeding can delay the return of your periods. But when you get your first period after birth depends on many other factors, such as how often you feed your baby, whether you offer them a dummy or supplementary formula feeds, and whether they sleep through the night. Most people experience their first period around six to 18 months after giving birth. Even if you’re breastfeeding and you haven’t yet started your periods, you can get pregnant, so it’s a good idea to use contraception when you have sex.

Medically reviewed by Sophie Martin, Lead midwife

Written by Joanne Lewsley | 16 Jul 2024

Photo credit: Erica Cervantez for BabyCenter

Is it normal for my periods to start while I’m breastfeeding?

Breastfeeding can delay the return of your periods, especially if you are exclusively breastfeeding your baby. Experts call this ‘lactational amenorrhea’. Feeding your baby stops certain hormones from releasing, which are important to ovulation (Gill 2016).

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However, when you get your first period after birth depends on how often you breastfeed, whether your baby is sleeping through at night, and whether they’ve started solid foods yet (Gill 2016, HSE 2022, LLLC 2023). It can also vary hugely from person to person (LLLI 2021). While your periods can be delayed for several months, or even years, while breastfeeding, it’s also possible to have a period within a few months of giving birth (Gill 2016).

Most people who are fully breastfeeding become fertile and start their periods again between six and 18 months after giving birth (LLLC 2023, LLLI 2021, Yanniarti et al 2023).

You're more likely to get your periods back sooner if:

Your baby is sleeping for more than four hours at a time during the day, or is sleeping for more than six hours at a time at night.
Your baby has begun to eat solid foods.
You are supplementing some breastfeeds with formula milk.
Your baby uses a dummy.
Your baby is feeding less often during the day, and for less time at each feed.

(HSE 2022, LLLC 2023)

Your periods are less likely to return if:

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You're feeding your baby on demand.
Your baby hasn’t started solid food yet.
You don’t offer your baby a dummy.
You don’t give your baby supplementary formula feeds.
Your baby still wakes at night for feeds.

(HSE 2022, LLLC 2023)

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When your periods return also depends on the level of the hormone progesterone in your body.

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If you have lower levels of progesterone, you're likely to get your periods back earlier than people with higher levels (Ingram et al 2004).

So it's possible that you could be breastfeeding around the clock, but still become fertile and start your periods again. While it’s unlikely to happen, it is possible to get pregnant within three weeks of giving birth, even if you’re breastfeeding and you haven’t started your periods (NHS 2024). So, if you don’t want to increase your family again just yet, it’s a good idea to use contraception when you and your partner have sex.

Is it normal to have irregular periods while breastfeeding?

While breastfeeding, your periods may be irregular and unpredictable compared to your periods before having your baby. You might find that they’re longer, shorter, or even absent for several months (Gill 2016).

More breastfeeding advice and information:

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Sources

BabyCentre's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organisations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.

Gill K. 2016. Spotting and Irregular Periods: Normal While Breast-Feeding?. Healthline. www.healthline.com Opens a new window [Accessed June 2024]

HSE. 2022. Breastfeeding and fertility. HSE. www.2.hse.ieOpens a new window [Accessed June 2024]

Ingram J, et al. 2004. The association of progesterone, infant formula use and pacifier use with the return of menstruation in breastfeeding women: a prospective cohort study. Eur J Obstet Gynecol Reprod Biol. 004 Jun 15;114(2):197-202www.pubmed.ncbi.nlm.nih.gov/Opens a new window [Accessed June 2024]

LLLI. 2021. Menstruation. La Leche League International. https://llli.orgOpens a new window [Accessed June 2024]

LLLC. 2017b. Breastfeeding and teething. La Leche League Canada. https://lllc.ca Opens a new window [Accessed June 2024]

NHS. 2024. Your body after the birth. NHS, Health A-Z. www.nhs.ukOpens a new window [Accessed June 2024]

Yanniarti S, et al. 2023. The relationship of exclusive breastfeeding with the return of menstrual time in mothers who have babies aged 6 -12 months in the work area of Pekik Nyaring Puskesmas, Bengkulu Central District. Indonesian Journal of Nursing and Midwifery. Vol 11, No 1. https://ejournal.almaata.ac.id/ Opens a new window [Accessed June 2024]

Joanne Lewsley

Joanne Lewsley is a freelance copywriter and editor, and specialises in creating evidence-based parenting, health and lifestyle web content.

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I'm breastfeeding, so why have my periods started again?

Is it normal for my periods to start while I’m breastfeeding?

Is it normal to have irregular periods while breastfeeding?

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