Applicability of GST

I am a doctor (registered with Medical Council of India) dispensing allopathic medicines only to my own patients. I take a composite charge (fee + cost of medicines together) from them. I have been buying those medicines from distributors paying GST along with the cost of the medicines. Should I take GST registration? Or do I have to maintain specific records? Incidentally my annual turnover is Rs 20 lac +. and the distributors are giving me GST tax invoices against my PAN. Thanks