Hello dear, First of all, HIV cannot be diagnosed only on the basis of symptoms. The ulcers as mentioned in your post can be Apthous ulcers, attributed to nutritional deficiency, local trauma or stress. Kindly visit your General Physician for proper clinical evaluation. Symptomatic relief can be obtained with application of topical analgesic anti- inflammatory agents + topical antiseptics. However, to relieve your concern regarding HIV infection, you can undergo certain tests like p24 assay or PCR for HIV, which becomes positive within a week and are almost 100 % sensitive. Even the presence of a single virus in the body can be detected by PCR. So, if this test comes negative, you can be sure that you are safe. Wishing you a good health. Take care.