Taking birth control pills for contraception includes long-acting birth control pills, short-acting birth control pills, emergency contraceptive pills, and so on. 1. Long-acting contraceptive pills: through the inhibition of ovulation, inhibit the fertilization of the egg to achieve contraceptive effect, including levonorgestrel ethinyl estradiol tablets, estradiol cyclopentyl ether and so on. Adverse reactions are similar to early pregnancy reactions such as drowsiness, fatigue, breast swelling and pain. Contraindications are hepatic and renal insufficiency, history of thrombosis, hyperthyroidism and so on. 2. Short-acting contraceptives: are compound drugs containing estrogen and progesterone, by changing the endometrial environment, inhibit ovulation to achieve contraceptive effect, including drospirenone ethinyl estradiol tablets, ethinyl estradiol cyproterone tablets. Adverse effects are milder than those of long-acting contraceptives, and may include amenorrhea and irregular vaginal bleeding. Contraindications include obesity, gynecological tumors, hypertension and so on. 3. Emergency contraceptive pills: after unprotected sex, through the inhibition of ovulation to achieve contraceptive effect, including levonorgestrel, mifepristone and so on. Adverse reactions are more and more serious, such as menstrual disorders, dizziness, headache and so on. Contraindications are suspected to have been pregnant, severe asthma and so on. If there is no birth plan, reasonable contraceptive measures should be taken in time, and suitable drugs should be selected under the guidance of doctors for contraception.