2. THE ONION TEST
While the Ancient Egyptians were on to something with the wheat and barley test, they and the Ancient Greeks seem to have had a fuzzy understanding of anatomy. Both Egyptian medical papyri and Hippocrates, lauded as the father of medicine, suggested that a woman who suspected she might be pregnant insert an onion or other strong-smelling bulbous vegetable into her vag*** overnight. If her breath smelled of onions the next morning, she wasn’t pregnant; this was based on the idea that her womb was open, and wafting the oniony scent up to her mouth like a wind tunnel. If she were pregnant, then the womb would be closed, so no wind tunnel.
This seems identical (or very similar) to our Sages understanding of women's biology, as the Talmud in Ketuvot 10b says as follows:
Someone came before Rabban Gamaliel the son of Rabbi [and] said to him, 'My master, I have had intercourse [with my newly-wedded wife] and I have not found any blood.' She [the wife] said to him, 'My master, I am still a virgin.' He [then] said to them: Bring me two handmaids, one [who is] a virgin and one who had intercourse with a man. They brought to him [two such handmaids], and he placed them upon a cask of wine. [In the case of] the one who was no more a virgin its smell went through, [in the case of] the virgin the smell did not go through. He [then] placed this one [the young wife] also [on a cask of wine]. and its smell did not go through. He11 [then] said to him: Go, be happy with thy bargain. — But he should have examined her from the very beginning! — He had heard a tradition, but he had not seen it done in practice. and he thought. The matter might not be certain and it would not be proper18 to deal lightly with daughters of Israel.
Therefore, it would be a denial of the scientific knowledge of Chazal to use any other method of detecting pregnancy. Bring Back the Onions! (and save the rabbits)