CPT® code 96372, Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular, should be reported for each intramuscular or subcutaneous injection performed. Therefore, if two or three injections are performed, it would be appropriate to separately report code 96372 for each injection. Modifier 59, Distinct Procedural Service, wouldbe appended to the second and any subsequent injection codes listed on the claim form. Note that for professional reporting, code 96732 requires direct physician supervision. It is reported per injection, even if more than one substance or drug is in the single injection.
You didn't specify the type of injection you are doing, so you should verify that you are reporting the correct injection code.