Edward Bury
Edward Bury voted up Cookie Roma's answer

Of course you COULD be pregnant.  I have a friend who has 3 kids. While she was married and they wanted children, she could never tell until she was 7 or 8 months along. 

Edward Bury
Edward Bury voted up Angela Anthony's answer

Yes absolutely you can be pregnant without symptoms. Many women go months without knowing they're pregnant, some even the entire pregnancy.