Usually, after ovulation promotion or after the normal follicles have developed and matured, when the follicles do not expel normally due to endocrine hormonal imbalance in the ovaries, an egg-breaking injection is needed. Ovulation breakers are HCG injections that promote follicle rupture and discharge. Generally, the follicles will be discharged within 38 hours after the injection; in some cases, the follicles will be discharged within 12 hours after the injection. Therefore, 12 hours after the injection, the doctor will recommend to arrange intercourse, which has the highest chance of conception.