Odds are if you threw up after smoking your pipe it was related to nicotine. If not, it was most likely unrelated.
If a tobacco tastes so bad and offensive as to trigger your gag reflex and turn your stomach, then I can't see anybody smoking it long enough to cause you to get sick in the first place...
With that said, I still cannot smoke a particular cherry cavendish because I smoked it on the same night I got food poisoning; ever since I have bad associations with the smell, let alone the taste of that blend...
It is a mistake to assume you are automatically up for the nicotine challenge of some blends even though you smoke cigarettes. There are blends out there that can really pack a wallop in a short amount of time, as opposed to the short bursts of nicotine that cigarettes provide.
Guys who chew or dip are probably the least likely to feel nicotine because they release high amounts of nicotine over an extended period.
If you feel dizzy, your heart races, you sweat, you feel nauseous - that's probably nicotine.
If you just get sick to your stomach on one occasion, then maybe its the blend somehow but first I'd examine what you've eaten.