Pulmonary Embolism (PE): Sudden onset of hemoptysis and pleuritic chest pain in a young adult without a history of tuberculosis (TB) contact or symptoms of infection (like fever) makes PE a leading consideration. The absence of weight loss and fever also points away from chronic infections or malignancies.

Pneumonia: Although the patient denies fever, atypical pneumonia could present with hemoptysis and pleuritic chest pain. The lack of fever does not entirely rule out pneumonia, especially if it's an atypical bacterial infection.
Bronchitis: Acute bronchitis could cause hemoptysis, especially if it's severe. However, the presence of pleuritic chest pain is less typical for bronchitis alone.
Mitral Stenosis: This condition can lead to hemoptysis due to pulmonary congestion. However, it would typically be associated with other symptoms such as dyspnea, orthopnea, or palpitations, and might not fully explain the sudden onset of pleuritic chest pain.

Tuberculosis (TB): Despite the denial of TB contact, TB can be asymptomatic in contacts, and the presentation can be atypical, especially in immunocompromised patients or those with HIV (though not indicated here). TB is a critical diagnosis not to miss due to its public health implications and the need for specific treatment.
Lung Cancer: Although rare in young adults, lung cancer can present with hemoptysis. The absence of weight loss or other systemic symptoms does not rule out early-stage disease.
Goodpasture Syndrome: An autoimmune disease that can cause hemoptysis and renal failure. It's rare but critical to diagnose early due to its potential for severe outcomes.

Wegener's Granulomatosis (Granulomatosis with Polyangiitis, GPA): A systemic vasculitis that can present with hemoptysis among other symptoms. It's rare and would typically be associated with other systemic symptoms or renal involvement.
Pulmonary Arteriovenous Malformation (AVM): A congenital condition that can cause hemoptysis due to the abnormal connection between pulmonary arteries and veins. It's rare and might not have other associated symptoms.
Catamenial Pneumothorax: Associated with endometriosis, this condition can cause recurrent pneumothorax and could potentially lead to hemoptysis if there's associated pulmonary injury. It's rare and typically occurs in relation to the menstrual cycle.