Well, that is not black, but dark gray, so it should be "fairly" thin - nearly clear - but still a little density and a little detail.
If your negatives are very substantially underdeveloped, even a "Human Densitometer" will be able to say so. Slight variations are the province of more precise instrumentation. Printing them tells all.
Please note that all the advice so far has referred to the most widely used interpretation of what a normal negative should look like, where the negative recieves just enough exposure to attain the tonalities desired. Some workers, many large format shooters among them, bump up exposure to some degree, to get shadow detail a bit higher up the characteristic curve. I am not talking vast extra exposure.
There are exceptions. A very - very - few deliberately expose quite a bit heavier to get an all over notably darker negative. I think I remember that Ralph Gibson did that. Somewhat different tonalities result I think, as well as exaggerated grain, and I suspect much more demanding to print.