Before a girl gets married, she must remove her Nidda status by going through the standard procedure that married women must go through after becoming a Nidda. This means that she must ascertain the cessation of bleeding through the "Hefsek Tahara," and then make two Bedikot (inspections) each day (morning and afternoon) for seven days. At the end of the seven days, she immerses in a Mikveh. The only difference is that a bride may immerse on the seventh day, whereas a married woman may immerse only after nightfall.
This information is well-known and taught in standard marriage preparation classes, but it has recently come to my attention that some people are under the misconception that a bride preparing for her wedding does not have to make internal inspections. This is entirely incorrect; a bride must make the same Bedikot as married women. It is true that a girl who had never been married might be physiologically unable to check herself the same way a married woman does. However, Halacha requires her to inspect to the extent that she can. If, for whatever reason, she is unable to make both daily inspections each of the seven days, she should consult with her Rabbi for guidance. In some situations, there is room to permit a woman to make fewer inspections. But a bride is certainly under the same obligation to make Bedikot as married women.
It is unclear where this misconception comes from, but it might have originated from the Bet Yosef (Yoreh De’a 192), who does not mention Bedikot when discussing a bride’s preparations for her wedding. However, the Bet Yosef was likely referring to the times when even single girls would immerse in the Mikveh after menstruation, and therefore a bride before her wedding could have already been Tehora (ritually pure). As such, Bedikot were unnecessary. Nowadays, however, girls do not immerse in a Mikveh until before their wedding, and thus their process of purification is required on the level of strict Torah obligation. Hence, their Bedikot are obligatory. This Halacha is mentioned explicitly by Hacham Ovadia Yosef, in his Taharat Ha’bayit (vol. 1, p. 471; listen to audio recording for precise citation).
Summary: Before a girl’s wedding day, she must perform Bedikot for seven days just as a married woman does after becoming a Nidda. If a bride cannot, for whatever reason, make all the required inspections, she should consult with her Rabbi for guidance.
