menstrual cycle vs fertile phase

menstrual cycle and fertile phase both are nouns.

Word	Noun	Adjective	Verb	Adverb
menstrual cycle	Yes	No	No	No
fertile phase	Yes	No	No	No

menstrual cycle (noun)	fertile phase (noun)
a recurring cycle (beginning at menarche and ending at menopause) in which the endometrial lining of the uterus prepares for pregnancy; if pregnancy does not occur the lining is shed at menstruation	the time in the menstrual cycle when fertilization is most likely to be possible (7 days before to 7 days after ovulation)