Keritot, Chapter Six, Mishnah Five
1) If a woman is liable to a bird hatat brought in a case of doubt and Yom Kippur intervenes, she is still bound to offer it after Yom Kippur, because it renders her fit to eat sacrifices.
2) If a hatat of a bird was brought for a matter of doubt and, after the pinching of its neck it became known [that there was no need for it], it must be buried.
Section one: In yesterdays mishnah we learned that if a person was liable to bring an asham talui because he might have sinned, and Yom Kippur intervenes, he is no longer liable to bring the asham talui. In contrast, today we learn that if a woman is liable to bring a doubtful hatat because she had a miscarriage that might or might not make her liable to bring a hatat, she must bring the bird hatat even if Yom Kippur comes first. The reason she must bring the hatat is that without doing so she cannot eat sacrifices.
Section two: If the woman finds out that she didnt need to bring the hatat, but the bird neck has already been slaughtered by having its neck pinched, then it is treated like a non-sacred bird slaughtered in the Temple which must be buried. This is different from a bird hatat that is brought in a case of doubt which is burned (see Temurah 7:6).