Sayang, aspirin boleh sebabkan nausea atau muntah untuk some people, especially on an empty stomach, tapi kalau suddenly kena demam, batuk, and muntah semua at the same time, that sounds like benda lain (maybe virus ke?) rather than just the aspirin. Please check with your doctor or go to a clinic ASAP , kena make sure it's not something yang kena treat separately, especially since you're on metformin. A few of my mum friends pun kena confused between medication side effects dengan actual infection, so better safe than sorry! Your doc can confirm if it's the aspirin or something else, and adjust accordingly. Take care of yourself!