The early stage of pregnancy is a critical period for embryo development, and intercourse is not recommended in the early stage of pregnancy. Firstly, the embryo is not stable in the early stage of pregnancy, so under the external force of intercourse, the embryo may detach from the endometrium and cause miscarriage to occur. Secondly, after sex, the vaginal environment changes from acidic to alkaline. In an alkaline environment, the vagina is susceptible to infection by pathogenic microorganisms, which can cause vaginal inflammation. If vaginal inflammation occurs during pregnancy, it can affect the development of the embryo and even cause miscarriage. Finally, orgasm during sexual intercourse can induce uterine contractions, which are a key factor in causing miscarriage. It should be emphasized that it is not certain that the above-mentioned adverse pregnancy outcomes will occur after intercourse. If a pregnant woman accidentally has intercourse in the early stages of pregnancy, she should not be overly concerned and is advised to pay attention to abdominal pain and vaginal bleeding. If there is no abdominal pain or vaginal bleeding, you can observe at home; if abdominal pain or vaginal bleeding occurs, you should consult a local hospital for relevant laboratory tests and, if necessary, fetal preservation treatment. In conclusion, it is not recommended for pregnant women to have intercourse in the early stages of pregnancy.