It makes sense from an evolutionary standpoint: The best time to mate is when your fertility is at its peak. During ovulation, your estrogen levels rise, boosting blood flow, which gives you rosier cheeks and redder lips. Your voice comes out just a little bit higher—a subconscious signal to men that you are at your most fertile—and you even smell better (biologically speaking), triggering a response in men that’s linked to romantic courtship and behavior.

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