21 years old and just starting my hair loss treatment

So I went to a GP as I wanted to get a prescription for Finasteride. Of course the doctor had never heard of the drug and apparently he had never had anyone come to him about hair loss. He started reading about the drug online and asked if I had tried minoxidil. I told him that I have been on minoxidil for two weeks but I wanted to use both treatments together. He responded to this by telling me that I should only use one treatment at a time and that I would have to choose which one I wanted to use. I told him I’d choose Finasteride and he wrote me script for it. I’m still considering using the two treatments together as I can’t find anywhere that says there’s something wrong with using these two treatments together. Has anyone else heard of this before and do you think that I should still use Minoxidil and Finasteride together anyways?

Brief History: I’m a 21 year old male, started noticing my hairline receding 2 years ago, it has been receding very slowly ever since but my hair loss has progressed to the point where I need to stop it before it becomes too noticeable. No hair loss on the crown and all my hair is still very thick.

If you have a balding or thinning area already, using minoxidil on it in addition to finastetide is something I often recommend. I like to get a HAIRCHECK test on all of my patients to be able to measure the progression or the reversal of hair loss while you are under treatment.