If you’re wondering when to restart birth control after ulipristal emergency contraception (UPA), wait five full days: restart a progestin-containing method on day six. Use condoms or avoid vaginal sex during the wait and after restarting until your method is effective. Plan a pregnancy test after emergency contraception for three weeks after your most recent unprotected sex.
Why You Need To Wait Five Days
UPA works partly by delaying ovulation. Progestins—the hormones in many pills, implants, injections, hormonal IUDs, patches and rings—could interfere with that effect if you take them too soon. Restarting early may make UPA less able to delay ovulation; UPA may also affect how well your regular contraceptive works.
The CDC’s 2024 U.S. Selected Practice Recommendations advise starting or resuming pills, patches or rings no sooner than five days after UPA. WHO guidance says to restart progestogen-containing methods on the sixth day. These instructions mean the same thing: wait five complete days, then restart on day six.
The concern is based on studies that measured ovarian activity, not pregnancy outcomes. A CDC review of four studies found that two saw more ovulation when oral contraceptives were started within five days of UPA than when they were delayed. This supports the waiting advice, but it does not tell us exactly how much early restarting changes an individual’s chance of pregnancy.
What Backup Contraception To Use
Use condoms or avoid vaginal sex during the five-day wait. After restarting, keep using condoms or avoid sex until your regular method has had time to work. For many methods, that means seven days after restarting; timing can vary by method, so check its instructions or ask a pharmacist or clinician. If you have unprotected sex during the wait, UPA does not protect you from that later sex.
The advice is broadly similar in U.S. and WHO guidance for restarting oral contraception. There is a difference for methods that require a clinic visit: the CDC says starting an injection, implant or IUD at the time of UPA may be considered after weighing the possible interaction against the risk of delaying regular contraception. WHO says a copper IUD can be inserted immediately; it also allows immediate insertion of a hormonal IUD if pregnancy can be ruled out. These options need individualized advice. The CDC and WHO guidance does not establish the exact current policy in every country, so check local instructions in the UK, EU or Australia with a sexual-health service or pharmacist.
Pregnancy Test After Emergency Contraception: When To Test
Take a home pregnancy test three weeks after your most recent unprotected sex. If you have unprotected sex again during the waiting period or before your regular method is effective, count three weeks from that later date. Testing too soon may not give a reliable answer.
UPA can shift the timing of your next period, so bleeding earlier or later than expected does not by itself confirm whether you are pregnant. Emergency contraception does not prevent every pregnancy. If you have not had a period or withdrawal bleed within three weeks, take a test; seek advice from a clinician or sexual-health service if the result is positive, or if you remain concerned after a negative result.
If You Already Restarted Early
If you took a progestin-containing method within five days of UPA, contact a pharmacist, prescriber or sexual-health service for advice about your specific method and any sex since taking UPA. Don’t assume that emergency contraception covered sex after the dose. Use condoms or avoid sex while you clarify your next steps.
This timing advice applies to UPA, not levonorgestrel emergency contraception such as Plan B, which has different restart guidance. If you are unsure which emergency contraceptive you took, check the package or ask a pharmacist. A clinician can help you interpret your timing and pregnancy-test result.
