here are varying opinions about the number of bedikot one performs during an onah. Some say only one bedikah at any point during the onah is required, although there are opinions that require two (one at the beginning of the onah, and another at the end) or even three (beginning, middle and end). Some authorities maintain that a bedikah right after the onah is also sufficient.

A veset she’aino kavua is cancelled once the day passes and you do not begin menstruating. Therefore, even if you did not perform a bedikah on the onah, the onah does not carry over and is not observed the following month.

If a woman inadvertently omits her bedikot on her onot perishah, she need not make up for them later.  The exceptions are the onah beinonit or a veset kavua.  If no bedikot were performed on these onot, relations may not resume until a bedikah has been performed.

You may want to review our site’s articles on Vesatot for more details.