According to scientific publications, the pain caused by applying forces to the teeth starts about two hours after braces or aligners are fitted, peaks after 24 hours and gradually eases over the following days, being least noticeable around the seventh day. Some studies show that taking ibuprofen up to an hour before the braces are fitted can reduce how intense the pain is afterwards. Aspirin and paracetamol have also been shown to be effective at relieving pain, with paracetamol providing a stronger effect for around six hours after it is taken.
This answer is for general information. Your own case needs an examination by an orthodontist.