Is 7 on my bun something to be concerned about ?

Nope.: An elevated BUN level is much more concerning than a marginally low one like yours. When high, the BUN means your kidneys are not working well (can also indicate things like a urinary tract obstruction, congestive heart failure, or dehydration). A low BUN level could indicate liver disease, but this is very unlikely at the level you mention, and would likely show up in other tests you had.