Hello kollel, another question!
We see a woman needs to wait 3 months before yibum , in order to make sure she's not pregnant.
Two questions: why do we not release her when she gets her menstrual cycle? That would seem clear evidence she's not pregnant. Is she not niddah if she sees blood during this time? If she is it seems to be a stirah in the metzius...she's either niddah or she's pregnant but not both...
In the modern era of accurate pregnancy tests do we still need 3 months?
Thank you!
1) The third Mishnah in the first chapter of Masheches Nidah states in the name of Rebbi Eliezer that there are four types of women who are "Dayan Sha'atan." The Bartenura writes that this means that they are not accustomed to menstrual bleeding. One of these women is a pregnant woman. The fourth Mishnah states that she is considered pregnant for this purpose when it is noticeable that she is pregnant. The Bartenura writes that this is three months after becoming pregnant. We learn from this that bleeding is only unusual for a pregnant woman after three months, so a menstrual cycle in the first three months would not provide evidence that she is not pregnant. She is a Nidah if she sees blood during this time (see Shulchan Aruch, Yoreh Deah 189:33).
2) The Gemara (Yevamos 42b) states that there is a Gezeirah of Chazal that even a woman who is not capable of having children also must wait three months. The Teshuvos Rivevos Efrayim (8:602, at end) writes in the name of Rav Moshe Feinstein zt'l that a pregnancy test does not help.
B'Hatzlachah Rabah,
Dovid Bloom