Yohtex is a trade name, generic name is levonorgestrel tablets, taking levonorgestrel tablets in general the probability is that you will not get pregnant, there are a very small number of patients contraceptive failure, unwanted pregnancy. Levonorgestrel is an emergency contraceptive. Generally speaking, if in accordance with the prescribed time, within 72 hours after unprotected sex for oral intake, the earlier the oral intake of the better effect, the correct use of its pregnancy rate of 4%, so it is not 100% will not get pregnant. Emergency contraception is only effective for one time of unprotected sex, the contraceptive efficiency is significantly lower than the regular contraceptive methods, and emergency contraceptive pills have a large dose of hormones, side effects are also large, can not replace the regular contraception. If you have any discomfort after using emergency contraception, it is recommended that you seek medical attention.