2,093. A Designated Time (Veses)
Hilchos Issurei Biah 8:1
Some women have a set time when they expect their period (veses) and others don’t. The latter feel nothing until the blood actually flows and they don’t have a fixed day for their periods to begin. When we say that a woman has a veses, we mean that there’s a specific day for her period to begin, such as from the 20th of one month to the next, or the 24th, etc.
Hilchos Issurei Biah 8:2
Before a woman’s period begins, she may exhibit some physical symptoms like yawning, sneezing, trembling at the opening to her bowel, hairs standing on end, her flesh feeling warm, etc. She will exhibit one or more symptoms at the established time when her period will begin on the designated day.