Trans men of reddit who take testosterone, when you get HRT blood work for the first time, can they review the nicotine content in your blood?

Depends on the test they administer. Different docs will administer different tests. More than likely, no, they will not look for nicotine. This question, by the way, is probably better suited for a trans focused subreddit. Also, maybe you should quit nicotine if it’s something you’re concerned your doctor will find out about.