YD 183: NOT WAITING SEVEN DAYS BEFORE RESUMING MARITAL RELATIONS AFTER PRE-CONVERSION MENSTRUATION
Since Gentiles are not bound by the laws of menstruation, a giyoret who had menstruated before her conversion does not have to wait the required seven clean days before (remarrying and) cohabitating with her husband. However, a woman who converts while she is menstruating is rendered a nidda immediately upon her conversion.
YD 189: CALCULATING A MENSTRUAL CYCLE (A VESET)
A giyoret calculates her veset from her pre-conversion cycle. This is because menstrual cycles are based purely on biological phenomena.
YD 192: DELAYING QUICK MARRIAGES ENTERED OUT OF DESIRE (CHIMMUD)
Although a couple must normally wait a minimum of seven days between an accepted proposal or a betrothal and the actual marriage due to concern about any excessive desire [on her part], a converting married couple does not have to wait before marrying again in accordance with halacha. This is because there is no concern about excessive desire.