Responsa for Niddah 31:10

מדאמר הונא חברין משמיה דרב אשה שיש לה וסת והגיע שעת וסתה ולא בדקה ולבסוף ראתה חוששת לוסתה וחוששת לראייתה אלמא וסתות דאורייתא

Thus<span class="x" onmousemove="('comment',' Since the possibility of a discharge at the time of the settled period is taken into consideration presumably even where no subsequent discharge had been observed. It is now assumed that 'discharge' was mentioned only on account of the second clause, 'the possibility&nbsp;… on account of her observation'. ');">¹⁰</span>

Teshuvot Maharam