The addiction part of this always is subjective but lets not pretend like that isn't a obvious recreational dosage at least 30mg 10-20 can be more common medically.
However 3 continual weeks day in and day out of using any drug is going to have some chemical hooks, weather you want to or not with continuing the drug might have little affect on how you feel coming off and more so you just like the feeling, that would be addiction mentally, and while not certain its probable to say the least. As for how you take it can affect this all at once, once a day or multiple times throughout is more likely to become dose dependant and withdrawal but none of this is a set in stone going to happen scenario again its highly subjective but I'm going to put my guess out there and say your more likely than not going to form certainly a physical dependence of some sort even if hardly noticeable, as for mental who knows but again more likely than not.
With out any more information on your past drug usage, etc.