Astanga Hrudaya
स्वस्ताक्षिकुक्षिं पुंस्कामां विद्यादृतुमतीं स्त्रियम्। पद्मं सङ्कोचमायाति दिनेऽतीते यथा, तथा॥२१॥
has throbbing in the pelvis and breasts,eyes and abdomen slightly drooping down and who longs for a male (for company and copulation)should be understood as a menstruating woman Just as the lotus closes at the end of the day, so also, the yoni (uterus, vaginal tract) after the rtu kala (the period suitable for conception);
english translation
svastAkSikukSiM puMskAmAM vidyAdRtumatIM striyam। padmaM saGkocamAyAti dine'tIte yathA, tathA॥21॥
hk transliteration by Sanscript