Sinus pressure on left side of face nose running a little bit pain in face when leaning over slot headache no cough no sore throat no fever?

Sinus infection: Sinus infection most likely. Viral cause most often and resolves in 10-14 days. Bacterial/fungal infections may require treatment. If it is worsening after 5 days, severe pain, if you can't smell very well, or this is a recurrent problem (annual sinus infection or more often); then good idea to see a specialist for Immune System work up and evaluation for chronic rhinitis.