Pain in the chest without cough and no other symtopms.chests clean and blood preasure normal.could that be infection?

Any number of things: It depends on the type, location, and quality of the pain; no cough and no other symptoms like fever would make infection less likely. See a doctor for further evaluation.

Chest pain : Chest pain can be due to heart problem ( angina) pulled muscles in chest, pneumonia, pleurisy ( infection of pleura which is covering of lung ) , reflux , breast issues, rib fractures, skin infections. It's best to consult a doctor for detailed history and examination to find cause for your pain . http://patient.info/doctor/chest-pain-pro