The reason why leukorrhea is not necessarily pregnant before menstruation is as follows: 1. When a woman suffers from gynecological inflammation, such as vaginitis, endometritis, pelvic inflammatory disease and tubal inflammation, it can lead to leukorrhea abnormality. The amount of leukorrhea may increase and become sticky, or even appear to be leukorrhea pulling. In this case, the woman is not pregnant, at the same time, when pregnant, the white belt will not generally appear this situation, that is, there is no inevitable relationship between pregnancy and the white belt appeared silk, can not be inferred from this. 2, before menstruation of the female body’s hormone levels there will be a big change, such as estrogen, progesterone, sex hormones, the amount of these hormones will be a significant rise in the content of these hormones, which will indirectly affect the body of the substance metabolism, thus leading to the production of white belt. The metabolism of substances, which leads to the generation of leukorrhea when the leukorrhea traits will change, the leukorrhea becomes viscous can become filamentous, in the clinic is also very common.