The reason that I asked that is because I've been reading about some tobaccos being heavy in nicotine, but I don't see anyone saying that this statement was based on dizzyness nor feeling sick. I've been smoking mostly aros, since it's hard to find good tobacco in Brazil (there is a shop with a great selection, but it's far from where I live, besides being very expensive due to being imported), and there is one that I smoked that is very mild in flavour and I find it pleasant, but it leaves a strong taste in my mouth, and I thought that could be an indicator of nicotine content.
I'm not that concerned about the nicotine because I don't smoke too much, and I usually don't have time to smoke an entire bowl without having to let it and come back later, so I've never felt that "buzz". I have a tin of Peterson 3Ps that I will open in a few months, let's see how it will go.
Thanks everyone for sharing the information and experiences, I really appreciate that! This is indeed "the friendliest and most pleasant pipe forum in the world"