It wouldn't be PCP or crack or coke or whatever. Dealers don't put in much more expensive drugs in a bag of pot, sell it for the same price, just for kicks. You know how expensive PCP or coke is? Someone putting that in is just giving away their money. "Here, I'll throw in $30 worth of coke, for free, so you can get fucked up"

It could've been sprayed with something. People do this to reduce smell and increase weight.

OR, you bit off more than you could chew. I seen newbs throw up after smoking weed, I've even seen a person go into a seziure before. Not laced weed, too much, too fast, bad trip. Take it slower next time