This article discusses ethical and methodological aspects related to the ethnographic research conducted in a drugstore in the city of Rio de Janeiro, Brazil, in 2011 and 2012. The aim was analyzing the dynamics of emergency contraception commercialization by this drugstore, as well as the social interaction between the seller and/or pharmacist and the customer at the time the latter purchases the pill. The investigation is permeated by challenges related to the commercial nature of drugstores in the country, even though these commercial establishments are legally considered as having a "health-related interest". First, we introduce a discussion on the background of the fieldwork: the quest for research approval, both by the research ethics committee concerned and by drugstore owners. Then, the process of getting into the field is discussed from the perspective of the relations and positions taken by the female researcher and the subjects under analysis. The choice for ethnography in the private context of drugstores, aiming to identify the commercialization of emergency contraception, was crucial to apprehend the complex processes related to the subtle games of sexuality and reproduction control in this space. The interaction between the female researcher and the research subjects during fieldwork constitutes a socially constructed process, according to the specific circumstances that delimit the collection of data/the research, thus, the research method and the ethical attitude must be properly defined and clear for the researcher. They are interconnected, depending on a creative exercise and a critical evaluation of the researcher on her/his relations within the field.