Manusmriti
नोपगच्छेत् प्रमत्तोऽपि स्त्रियमार्तवदर्शने । समानशयने चैव न शयीत तया सह ॥ ४० ॥
Let him, though mad with desire, not approach his wife when her courses appear; nor let him sleep with her in the same bed.
english translation
nopagacchet pramatto'pi striyamArtavadarzane । samAnazayane caiva na zayIta tayA saha ॥ 40 ॥
hk transliteration by Sanscript