唯有大姨妈不会弃我
[wéi yŏu dà yí mā bù huì qì wŏ]
Translates into 'Only menstruation/Aunt Flo won’t abandon me' using colloquial language. The underlying sentiment is about having reliable things/people around even during tough times; here it is phrased with self-deprecating humor referencing menstrual cycle.