i had a nose job 6 months ago, now i have a hard bump acorss the bridge of my nose. is this normal?

Is this "hard bump" a visible irregularity, or just something you feel? If the nose looks good, I wouldn't touch it. At six months, there is still some swelling, and the bump may further change (for better or worse). Really, it is difficult to comment without knowing more about your situation. Sometimes, such "bumps" are easily corrected or improved by injectables in the office (deferring or avoiding surgical revision). see video