Indeed, an emergency contraceptive is most effective in preventing pregnancy when it is taken prior to ovulation.
A critical element of the menstrual cycle is the release of luteinizing hormone (LH) over a 24 to 48 hour period; this LH surge stimulates the ovary to release an egg.
EC pills effectively inhibit or delay the release of the egg if taken at the right time during the cycle. While levonorgestrel EC pills are effective only if taken before the LH surge, ECP containing ulipristal acetate can still work after the LH surge has begun,(but is no longer effective once LH reaches its peak concentration.
There is some evidence that ulipristal acetate can produce changes in the uterine lining, but whether these changes would impair the implantation of a fertilized egg is unknown.
You can wait until your period is late by at least one week, and then take a pregnancy test.
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Hi Anonymous,
Indeed, an emergency contraceptive is most effective in preventing pregnancy when it is taken prior to ovulation.
A critical element of the menstrual cycle is the release of luteinizing hormone (LH) over a 24 to 48 hour period; this LH surge stimulates the ovary to release an egg.
EC pills effectively inhibit or delay the release of the egg if taken at the right time during the cycle. While levonorgestrel EC pills are effective only if taken before the LH surge, ECP containing ulipristal acetate can still work after the LH surge has begun,(but is no longer effective once LH reaches its peak concentration.
There is some evidence that ulipristal acetate can produce changes in the uterine lining, but whether these changes would impair the implantation of a fertilized egg is unknown.
You can wait until your period is late by at least one week, and then take a pregnancy test.
Regards,
October 19, 2015 - 9:01amMaryann
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