Is my testosterone low? (make more sense of my medical results)

Ok so i went to the doctor today, a while back i had some blood work done to see if there was anything making me less energetic (i feel kinda tired all the time). So he checked my thyroid and androgens. Today in the office i asked him what the results were, he explained that my level was 17.6 (didnt give me the units of measurement) and the normal range is 8 to 28. So i was just below the middle of the range. I asked him what he would expect a 20 year olds testosterone level would be, and he admitted that he would expect more on the 28 side of things. I should note that his first question was if i had taken anything to boost my testosterone, in retrospect this indicates that he must've thought id done a cycle or something and didnt do a proper therapy afterwords. Ive never done any hormones or anything.

So what is this scale of 8 to 28? I looked on google for quite a while and couldnt find anything, also what kind of things can impact test. level, even to a large degree? I know i haven't been sleeping enough, i also haven't been eating as much as i should. I havent noticed any trouble building muscle really as far as i can tell thats normal for me.

Thanks for any replies! im worried about this.

I am not sure what that is
Usually you have 3 measurements,
your free testoserone,
your total testoserone
and there is one other one

For instance, my test was 263ng/dl range 400-1000
and my free was 1.2 range 0.8-2.4

Ya he should have given me more information, damn canadian doctors trying to get you out asap. The drawbacks of public healthcare.

So i should go in next time and ask for a test for those 3 then right?

You want to get tested for all your test and serum levels and just to be safe your estrogen levels too! I beleive the test is a Chem 20 here in the states.
But yes, you want to know all of your test levels and estrogen levels