A high dose of the hormone levonorgestrel prevents up to 85% of expected pregnancies. Whether it works or not depends not on chance and luck, but on very specific factors: the phase of the menstrual cycle and the speed of taking the drug.
1. Pills may not work if unprotected intercourse occurs during ovulation or immediately after it, when the egg has had time to leave the ovary. It is impossible to block an ovulation that has already occurred.
Ovulation occurs 12-15 days after the onset of menstruation. And if the menstrual cycle is regular, then you can roughly understand whether the drug will work specifically in your case.
If unprotected intercourse did not occur in the middle of the menstrual cycle and after that you quickly took levonorgestrel, it should work.
2. Now let's figure out how much time a woman has after unprotected intercourse to drink the remedy and it was effective. The maximum is 72 hours, that is, 3 days. But it is better to do it in the first 12 hours.
The statistic is like this:
- if the pill is taken in the first 24 hours after unprotected sex, then its effectiveness is up to 90%;
– if within 24-48 hours, the effectiveness is reduced to 70%;
- if you take the drug after 48-72 hours, the probability of preventing pregnancy will be 50-58%.
The sooner you drink the drug, the better.