Some people are very sensitive to the emotional and physical experience of sexual intercourse and will occasionally menstruate while having relations. Other women might have the same phenomenon of menstruation due to a gynecological disorder. Whatever the reason, if a woman does have this condition she should consult her doctor in addition to her rabbi.
1. If a couple was having sexual intercourse and the woman informed her husband that she just became niddah as she felt her uterus open and pour out blood. It is absolutely forbidden for the husband to pull out while still erect as he will be stimulated by that act. Such stimulation is considered as if he has intentionally had relations with a niddah. Instead the couple should wait without moving, until his erection subsides and he becomes flaccid. While they are waiting the couple should minimize, to the degree possible, any bodily contact between them, (i.e. the husband should lift himself up on his hands and knees). The couple should repent this sin, even though it was inadvertent.
2. If the couple remembered that it was the time that she was expecting to menstruate, during intercourse, they must immediately separate. If he is worried that he will ejaculate outside her then the couple should follow the suggestions of the previous law.
3. There is a very rare but troublesome condition which may plague a woman: That is menstruating as a result of sexual relations. Under certain conditions the couple must separate if this condition persists.
4. This rule only applies if she checked herself immediately following intercourse. If she then found blood she is considered to have menstruated as a result of sexual relations. If this happens the couple should consult their rabbi (and doctor) and follow his instructions carefully.
5. Additionally, if her husband finds blood even a very long time after having relations she is considered to have seen as a result of those relations.
6. If a woman who has a fixed period had relations close to the time that she was expecting her period: ie. she expects her period to come during the day and had relations the night before, this bleeding is not considered to have resulted from marital relations, rather it is considered to be her normal menstruation.
7. If there is a wound in the vagina which might be bleeding, the woman is not considered to have seen due to relations.
8. A woman who has such a wound which might be bleeding, is considered niddah and must do a hefseq betahara and count seven clean days and immerse without a beracha unless she is sure that the wound is bleeding. If she is certain that the wound was bleeding she does not become niddah, and may continue having relations with her husband.
9. If she knows that the blood from her wound looks different than her menstrual blood she can not assume the blood which looks like menstrual blood to be from the wound. If she sees what looks like menstrual blood she is niddah and if the menstruation occurred during intercourse, she is considered to have seen blood due to relations.
10. A woman is believed if she says that she has a wound and that it is bleeding. In such a case she is not niddah at all. The woman is believed even if such a claim is made during the "seven clean days."
11. If a doctor tells her that she has a wound he is believed. This is the case regardless of whether the doctor is not observant or even non- Jewish.
12. A woman who checks herself thoroughly and consistency finds a stain in the same location and does not find blood in any other spots can assume that these stains come from a wound in that spot, especially if in that spot she feels a little pain and feels nothing in other spots. In any event a rabbi should be consulted. 13. If a woman has a wound which is bleeding, and she also feels her uterus opening and her body shaking (or any other physical sensation usually associated with her menstruation) she cannot assume that the blood is from the wound. Rather she is considered Niddah and must behave accordingly. (The only difference being that she does not recite a blessing for the immersion because she is of uncertain niddah status.) This applies only if she had these feelings and saw the blood around the time she expected to menstruate, or an average period of 30 days from her last menstruation. In other times she can assume that the blood is from the wound.
14. A woman with a wound is not niddah even if she found blood stains. (see chapter discussing stains)
15. If a woman who has had her period three times from relations has seen a doctor who claims to have cured her through the use of accepted medical practice she may remain happily married to her husband.
16. If such a problem comes up even once there are several rules which need to be known. Your rabbi should be consulted, and often the aid of a doctor is required.
17. A woman who sees blood while urinating is not considered niddah as the blood is assumed to have come out with the urine and not from the uterus.