I understand what you are trying to say, but it sounds strange and potentially confusing. Presumably, by 'hairless' you mean that the scalp is hairless, and you are not referring to other parts of your body (legs, eyebrows, armpits, ...). And 'hairless' might also suggest that this is a congenital condition, or the result of chemotherapy, etc. I would say 'I used to have my head shaved' or something similar.