On monday evening i vomited once. late yesterday afternoon and still today my chest hurts. it hurts worse when i take a deep breath.

You could have: Strained your respiratory muscles/chest wall/ abdominal muscles, when you were vomiting. Try Advil for temporary pain relief. If persists, c ur doc.

Waiting game: Hard to know what is causing your pain. Could be just residual from the vomiting episode. Do you smoke or drink alcohol heavily? These two habits can irritate & put your lower esophagus & stomach linings at risk & can be painful. Starting from the beginning, why did you vomit? In meantime avoid those substances as well as aspirin & if vomiting or pain continues, need medical examination.