From the Guidelines
You may not be fully protected against pregnancy due to the delayed intake of your progesterone-only contraceptive pill. The time difference between Amsterdam and the UK is typically 1 hour (Amsterdam is ahead), meaning your pills were taken approximately 15.5 hours apart, which exceeds the recommended 3-hour window for maintaining effectiveness 1. According to the U.S. selected practice recommendations for contraceptive use, 2013, a dose is considered missed if it has been >3 hours since it should have been taken 1.
When the interval between doses exceeds 3 hours, the contraceptive effect may be compromised, potentially allowing for ovulation or reducing cervical mucus thickness that normally prevents sperm penetration. Key points to consider include:
- Take one pill as soon as possible if a dose is missed
- Continue taking pills daily, one each day, at the same time each day, even if it means taking two pills on the same day
- Use backup contraception (e.g., condoms) or avoid sexual intercourse until pills have been taken correctly, on time, for 2 consecutive days 1
- Emergency contraception should be considered if the woman has had unprotected sexual intercourse 1
Since you had sex 2 days ago, there is a risk of pregnancy. You should take your next pill at your regular UK time and use a backup contraception method (like condoms) for the next 48 hours, as it is estimated that 48 hours of POP use is necessary to achieve the contraceptive effects on cervical mucus 1. If you're concerned about pregnancy risk, consider emergency contraception if it's within the appropriate timeframe. For future travel across time zones, consult with your healthcare provider about how to adjust your pill schedule to maintain protection.
From the FDA Drug Label
Levonorgestrel tablet is emergency contraception that helps prevent pregnancy after birth control failure or unprotected sex. You should use levonorgestrel tablet within 72 hours (3 days) after you have had unprotected sex. The sooner you take emergency contraception, the better it works
You are taking a progesterone only contraceptive pill, not levonorgestrel tablet. The provided drug label does not contain information about your specific contraceptive pill. The FDA drug label does not answer the question.
From the Research
Progesterone Only Contraceptive Pill Efficacy
- The provided studies do not directly address the efficacy of a progesterone only contraceptive pill when taken at specific times in different time zones.
- However, studies 2 and 3 discuss the efficacy of levonorgestrel, a type of progesterone, in emergency contraception, suggesting that it can be effective in preventing pregnancy when taken within a certain timeframe after unprotected intercourse.
Time Zone and Contraceptive Pill Timing
- The difference in time zones between Amsterdam and the UK is 1 hour, with Amsterdam being 1 hour ahead of the UK.
- Given that the progesterone only contraceptive pill was taken at 5:40 in Amsterdam time yesterday and 20:15 in UK time today, it appears that the pill was taken approximately 22 hours and 35 minutes apart, assuming a 1-hour time difference.
Pregnancy Protection
- Study 3 suggests that levonorgestrel is highly effective when taken before ovulation, but its effectiveness decreases when taken after ovulation.
- Since the user last had sex 2 days ago, it is unclear whether ovulation has occurred or not.
- Without more information about the user's menstrual cycle and ovulation timing, it is difficult to determine whether the progesterone only contraceptive pill is still effective in preventing pregnancy.