It was fashionable in the past (especially in the United States) for women to think that they should 'douche', or regularly wash the vagina out with water or soap to keep things clean. In fact, this is irritating to the delicate acid-balance inside the vagina. It may also actually increase the risk of HIV transmission as cervical mucus is removed.
There is no such thing as a 'normal' level of discharge for all women. A woman needs to know what's normal for her and to take action if things seem suddenly different. As a general rule, though, any spotting between periods may be a sign of trouble and is worth taking advice about.