Which pills avoid pregnancy after 21 days?

The question "Which pills avoid pregnancy after 21 days?" is a bit unclear. It seems to be asking about pills that can prevent pregnancy after a 21-day period, possibly referring to a cycle length. It's important to note that no pill works retroactively. Pills must be taken before or around the time of potential conception to be effective. The provided reference speaks of a specific pill designed for contraception. Let's rephrase and address some possible interpretations of the question for clarity:

Possible Interpretation 1: What type of pill is taken to prevent pregnancy during a typical 21-day cycle?

• Answer: There isn't a pill specifically for a 21-day cycle. However, many hormonal birth control pills are packaged in 21-day cycles, followed by a 7-day break. For example, the "Unwanted 21 Days Tablet" from the reference is a contraceptive designed to be taken for 21 days.

  • Mechanism: According to the provided reference, the Unwanted 21 Days Tablet works in two main ways:
    1. It prevents the ovaries from releasing an egg (ovulation).
    2. It thickens the cervical mucus, making it harder for sperm to reach the uterus.
  • Usage: It would be taken daily for 21 days, followed by a 7-day break where one would usually have their period, and then restart again.
  • Important Note: These kinds of pills are not "after the fact" contraception; they must be taken regularly and consistently as directed to be effective.

Possible Interpretation 2: Are there any pills to prevent pregnancy if I have a 21-day cycle and I’m past that 21st day?

• Answer: No, not directly. Emergency contraception pills, often called "morning-after pills", can be taken up to 72 hours (some even up to 120 hours) after unprotected sex. These pills are not a substitute for regular contraception. They should be taken as soon as possible after unprotected intercourse. They work by delaying or inhibiting ovulation. However, if conception has already occurred, emergency contraception will not be effective.

• Pill Types: Emergency contraception pills include levonorgestrel or ulipristal acetate pills. These are different from regular birth control pills.

Summary

It is critical to distinguish between regular contraceptive pills, like the "Unwanted 21 Days Tablet," which need to be taken consistently for efficacy, and emergency contraception, which can help prevent pregnancy after unprotected sex but has time limits. There are no pills that prevent pregnancy "after 21 days" in the sense of reversing a pregnancy after that time.

Pill Type	Purpose	Timing
Regular Birth Control Pills	Prevent pregnancy during the entire cycle. For example, Unwanted 21 Days Tablet.	Daily (21 days on, 7 off)
Emergency Contraception	Prevents pregnancy after unprotected sex.	As soon as possible (within 72 to 120 hours)