Q: Is it natural to have prolonged periods after just starting birth control? I started taking the pill when I started my period and it still persists.
A: Irregular bleeding is the most common side effect of birth control pills. It is especially common during the first three months as your body adjusts to the hormones in the medication. However, other things (like sexually transmitted infections) can cause prolonged bleeding too. If the bleeding is especially heavy (more than a normal period), persists throughout the whole month or occurs only with intercourse – especially if you’ve stopped using condoms – you should see your women’s health care provider to make sure nothing more serious is going on.
The most common cause of irregular bleeding is missed pills, so make sure you are taking the pill every day, and at the same time every day.
Birth control pills can cause a lot of other side effects, especially bloating, nausea and breast tenderness. Most side effects resolve after a few months, but the clinicians in our Women’s Services Department usually recommend that you check in with your health care provider after your first 3 months on the pill to make sure everything is going OK. If you have any questions or concerns about birth control, they’re happy to answer them for you.
John A. Vaughn, MD
Student Health Services
The Ohio State University
There are many different causes of bleeding between periods. Some may not be anything to worry about, but seek medical advice if you're concerned. Irregular bleeding, such as bleeding between periods,
is common during the first few months of starting hormonal contraception, such as the:Hormonal contraceptives
- combined oral contraceptive pill
- progestogen-only contraceptive pill
- contraceptive patch (transdermal patch)
- contraceptive implant or injection
- intrauterine system (IUS)
If you're concerned about bleeding or it lasts longer than a few months, you should seek medical advice.
You may also bleed between periods if you:
- miss any combined pills
- miss any progestogen-only pills
- have a problem with your patch or vaginal ring
- are on the pill and are also sick or have diarrhoea
Other causes
Some other causes of bleeding between periods include:
- taking the emergency contraceptive pill
- injury to the vagina – for example, from having penetrative sex
- recently having an abortion – seek medical advice if you're bleeding heavily
- sexually transmitted infections (STIs) such as chlamydia – it's a good idea to get tested if you've recently had unprotected sex with a new partner
- recently having a miscarriage
- reproductive hormones not working normally – this is common in women approaching the menopause or in women with polycystic ovary syndrome (PCOS)
- stress
- vaginal dryness
- harmless changes to the neck of the womb (cervix) – this may be called cervical ectropion or cervical erosion
- cervical cancer – if you're aged 25 to 64, you should be having regular cervical screening tests to detect any changes to your cervix; even if you're up-to-date with screening tests, you should see a GP about irregular bleeding, particularly bleeding after sex, to eliminate the possibility of cervical cancer
- womb (uterus or uterine) cancer – this is more common in post-menopausal women and most cases of endometrial cancer are diagnosed in women over the age of 50; see a GP if you're over 40 and have bleeding between periods to eliminate the possibility of uterine cancer
- vaginal cancer or vulval cancer
- cervical or endometrial polyps – non-cancerous (benign) growths in the womb or the lining of the cervix
- fibroids
When to seek medical advice
If you're concerned about bleeding between periods, you should:
- see a GP
- visit a sexual health or genitourinary medicine (GUM) clinic
A healthcare professional will talk to you about your symptoms. Depending on your situation, they may suggest doing some tests, such as:
- tests for STIs, which may include an examination of your genitals
- a pregnancy test
- a cervical screening test, if you're aged 25 to 64 and not up-to-date with these
- a pelvic ultrasound scan
To diagnose some conditions, you may need an examination, such as:
- a speculum examination – a smooth, tube-shaped tool (a speculum) is inserted into your vagina to examine your vagina and cervix
- an internal examination of your vagina with gloved fingers (bimanual examination)
Find out the answers to more questions about women's health
Further information
- Heavy periods
- Period pain
- Stopped or missed periods
- Find services: sexual health
Page last reviewed: 5 November 2019
Next review due: 5 November 2022