Question:
If a woman starts staining a day or two before her period, does she need to mark those stains on the calendar? And what if she later finds blood on a bedika after becoming impure from a Kesem?
Answer:
If a woman begins staining before her actual period, she only records the date when her actual period begins. This applies even if she became impure from those stains. However, if she became impure due to a Kesem and then later found blood on a bedika—whether during Hefsek Taharah or during Shiva Nekiyim—she must record that date.
Sources: See Shaareiy Tohar Shaar 4:3; Shevet Halevi 3:118; Tzitz Eliezer 6:21; Peri Shalom 8; Shaareiy Tohar 41; Taharah Kehalacha 24:6 and 59; Nitei Gavriel 90:1-3
Other Opinions to count from Kesem: See Igros Moshe 3:51; Kaneh Bosem 1:86; Shevet Halevi 4:99; 2:75; Nitei Gavriel ibid
