Well, normally they shouldn't smell, or there might be a slight sour-milk scent; other odors and strange or bright colors should be a cause for concern.
Before answering this question, it is important to note that each pregnancy and each woman are unique, and each may have different symptoms and manifestations before childbirth.
Typically, before childbirth, women may experience increased vaginal discharge, which can be mucous or clear. However, the smell of sperm is not a typical sign before childbirth. If you have a smell that concerns you or causes discomfort, it is recommended to consult a doctor or midwife for advice and further recommendations.