大姨妈够腥不够甜
[dà yí mā gòu xīng bù gòu tián]
'大姨妈' is an euphemism for menstruation in Chinese culture; here the user humorously implies her feeling about this natural yet troublesome female process, which might bother her but also doesn't completely ruin her mood - she wishes it less annoying ('腥：unpleasant') and more joyful ('甜：sweet').