Patients with cleft palate usually have some degree of speech defects. This is mainly in the form of a nasal twang. This occurs because air escapes through the nose since the palate is short. You need to be evaluated:
1. by a speech therapist, if some improvement can be brought about by training.
2. for velo-pharyngeal incompetence - which essentially means to find out if your palate is very short. In such cases, an additional surgical procedure (pharyngoplasty) can help.
I must say that the speech can never be 100% normal, so you have to critically assess if additional surgery can make a substantial improvement.