If you're not on insulin, but on medication like metformin or another tablet, diet-controlled or some such, it's pretty safe to say you're a T2. Some turn out to be a T1, LADA, Mody much later on, but this is the basic assumption made. The tests to determine type are expensive, so they usually go with an educated guess based on age, symptoms and weight. If things go from bad to worse the additional testing can be done though.
If you are LADA (late onset T1) then you will be deteriorating over many months or years which confuses many GPs. If you have continued high BS despite low-carbing then LADA becomes possible as a diagnosis