Islam encourages us always to seek purity as Allah loves those who are pure. Thus, He says: (Truly Allah loveth those who turn unto Him, and loveth those who have a care for cleanness.) (Al-Baqarah 2:222).
We have loads of traditions of the Prophet ( peace and blessings be upon him) that urge us to maintain cleanliness. One of these traditions link the punishment in the grave because of not taking precaution to keep oneself clean against urine.
Regarding this issue, secretions of a woman fall into the same categories as secretions of a man; so mani [semen or seminal discharge], madhi [a white sticky fluid that flows from the sexual organs as a result of sexual excitement] and wadi [a thick, white fluid which may come after urination or due to other reasons such as illness] are all secreted by her. If madhi comes out, you need to wash your private parts and make wudu’ to be eligible for prayers. If it gets on the clothes, it suffices to sprinkle the area with water. In the case of wadi, it is subject to the same rulings as urine and you need to wash it away.
As for the secretions which come out of women and whether they are considered impure. The secretions which come out of a woman’s vagina are impure; they nullify her wudu’, and whatever parts of the body or clothing they touch become impure, so the woman has to do istinjaa’ (washing the private parts) and wash them away, then do wudu’ if she wants to pray. She must also wash the places on her body or clothing that are touched by them.
If semen comes out without intercourse, you will need to do ghusl. The Prophet (peace and blessings be upon him) commanded women to do ghusl if they notice seminal discharge, as was reported by al-Bukhari from Umm Salamah (may Allah be pleased with her) who said: Umm Sulaim, the wife of Abu Talhah, came to the Messenger of Allah (peace and blessings be upon him) and said, “O Messenger of Allah, Allah is not too shy to tell the truth. Does a woman have to do ghusl if she has an (erotic) dream?” He said, “Yes, if she sees water (fluid).” In this hadith, he (peace and blessings of Allah be upon him) commanded women to do ghusl if they see water, i.e., mani.
Accordingly, if a woman sees semen has come out of her vagina, even if it is only a little, then she has to do ghusl, because of the report to that effect. It is not sufficient for her to do wudu’ in this case unless the fluid which was emitted was not the kind of fluid for which ghusl is required, such as madhi (lubricating secretion) etc., in which case wudu’ is sufficient.
The key this is that, you should make sure whether this fluid is madhi or mani and act accordingly.