The mum-of-two is in the UK to promote her new track What About Us, while juggling parenting duties for her eight-month-old son Jameson.
With a hair and makeup done and looking glamorous, Pink shared the intimate snap with her 2.2million followers.
Holding one pump in place while holding her phone in the other she snapped the selfie and captioned with: 'And now this #pupmupthejam #mombreak'
It didn't take long for the multitasking pic to garner 286k likes, and the 5k comments were full of praise for the 37-year old.
One fan couldn't applaud Pink enough for her honesty: 'Wow, great, I know how difficult it is keep doing that every day but it is the best for the baby'.
Another said that the image had made them feel inspired: 'Just saw this online! Feel a little ridiculous hiding out in the bedroom pumping off baby milk! But this has inspired me. Thank you 😊'
'Thank you for showing all that us mommas do to feed our babies!' a third, who used the hashtag #reallife, commented.
Another poster celebrated not only Pink's breast pumping skills but also her amazing body: 'I saw the Abs before the pumps.#respect on both -- thanks for sharing #empoweredwomen,' they exclaimed.
One agreed: 'Normalizing breastfeeding and pumping. Just another reason why you rock,' followed by another who said: 'I never mastered expressing lol good on you! Even after 4 kids could hardly get a bloody drop!! 😂 you look fantastic x'
This isn't the first time that Pink - who also has six-year-old daughter Willow with husband Carey Hart - has won approval from fans with her candid social media posts. Earlier this year, she was praised as an 'inspiration' for sharing a breastfeeding selfie.
'Such an incredible role model for the entire female population of every age group,' one fan said at the time.