"That is not menstruation, rather it is a vein. Tell her not to pray for the period of time that her period used to last, then let her perform Ghusl and pray." She used to perform Ghusl for every prayer.
Sunan an-Nasa'i Book 3, Hadith 9
← Previous Hadith "That is not menstruation, rather it is a kick in the womb, so let her work out the length of the menses that she used to have, and stop praying (for that period of time), then after that let her perform Ghusl for every for every prayer."

Sunan an-Nasa'i Book 3, Hadith 8 Next Hadith → "That is a vein, so when your period comes, do not pray, and when your period is over, purify yourself and pray in between one period and the next." Abu 'Abdur-Rahman said: Hisham bin 'Urwah reported this Hadith from 'Urwah, and he did not mention what Al-Mundhir mentioned in it.

Sunan an-Nasa'i Book 3, Hadith 10