Well there is a couple of things that can happen
1. you will have the most amazing experience you have ever had, it will be like an awakening, beutiful colours, beutiful world.
2. you will freek out completely, turn into a paranoid freek, maybe end up a pyscophrenic,loose your confidence, and never be the same person you were, one of my friends was fucked up for 2 years after taking a bad trip.