The three BOOM drop by Q that you're referencing was made before the bombings. I don't think that if Q/MI had prior knowledge of these bombings that they would have allowed them to occur. Also, keep in mind that Q is not claiming to possess the power of prophesy. They have a well thought out plan. Which means that there must be a timetable. Which means that if a Q drop 'predicts' some occurence or another in the future, then it's only because there is a PLAN, and that plan is going according to schedule.
Trust The Plan.