Hi, I have been smoking weed (sometimes mixed with tobacco) for about a year now with no side effect besides what would be considered getting "high." However, twice in the past month, i have smoked bowls, exhaled the smoke, and within about 5 seconds I (according to the people with me when I smoked) i started to shake as If I was having a seizure and pretty much fainted to the ground. This would only last about 10 seconds altogether although I have pretty much no recollection of anything specific happening besides realizing that something werid happened by when I "woke up." Could this just be a bad/laced kind of weed or maybe the specific amount i smoked was too much for my lungs/head? or some sort of allergic reaction?