Feeling better often happens before the infection is fully gone. Bacteria can still be present even when symptoms ease, so stopping early on your own risks the infection coming back, sometimes harder to treat.
Follow the duration your prescriber gave you. If you want to stop because of side effects, or you are not sure how many days you were meant to take, contact your doctor or pharmacist rather than deciding alone.
Never save leftover antibiotics to use later or give to someone else. If your symptoms get worse despite taking the antibiotic, or you develop a new rash, breathing trouble, or severe diarrhoea, seek medical advice promptly.