A high dose of the hormone levonorgestrel blocks ovulation. And if there is no egg, then the sperm has nothing to connect with - and pregnancy does not occur. That is, emergency contraception does not cause medical abortion.
And if at the time of taking the drug, the sperm has already managed to merge with the egg (the probability of this is 15–20%), then the progestogen, on the contrary, even favors the implantation of a fertilized egg. Therefore, you should not worry that you somehow harmed the embryo if you took the drug, but the pregnancy did occur.
Usually hormonal preparations are female sex hormones that are produced by our own ovaries. Yes, there are natural and synthetic ones, and levonorgestrel is a synthetic substance, but still it is a female sex hormone.