Spanish VS. Portuguese

I must be getting a Portuguese accent or something when I speak Spanish because I have had about 3 different people compliment me on how good my Portuguese is... Meanwhile I don´t speak any Portuguese (only a few words) and am speaking Spanish to them the whole time although I am beginning to understand the Portuguese better after being in Brazil for more than 2 weeks now... Maybe it comes from being around a lot of people who speak Portuguese..... Not sure, but very interesting!!!