What would be the point of stopping to get blood work? To test what, exactly?
Everybody is different in how fast they may, or may not, return to pre-TRT LH and T levels. Remember too, that one doesn't go on TRT unless they have low T to begin with, so when you say "old levels of LH and T" you gotta remember that those are LOW levels - not the levels of a healthy 20 year old man, for example.