Swollen breasts in early pregnancy are not growing buds, but are the result of increased levels of estrogen and progesterone in the body after pregnancy. Pregnancy is a special physiological phenomenon. The increased level of estrogen and progesterone in the body after pregnancy causes the development of mammary gland follicles and ducts, thus making pregnant women feel breast swelling. Estrogen increases the growth of mammary gland ducts and connective tissues, while progesterone promotes the growth of mammary gland follicles, which synergistically promotes the further development of the breasts in preparation for the secretion of milk after delivery. The growth of fetal buds in the early stages of pregnancy is the cell division of the fertilized egg, and with the division of the fertilized egg cells, tissue differentiation and organ formation occurs, which leads to the growth and development of the embryo to form a fetus. Therefore, the early stage of pregnancy is also a period of drug sensitization, so if you need to use drugs need to be under the guidance of a doctor, do not take action to avoid affecting the development of the mother and fetus, resulting in an adverse outcome of pregnancy.