could be, but megathrust type earthquakes are often preceded by a large fore-shock. i'd be stocking some big jugs of water and canned food in a closet or in the basement for the next couple months just in case. a week or so of food and water will really help out if the stores go empty if the big one hits.

a few days before the 9.1 earthquake hit east japan, we experienced a fairly strong shake (around 7.1 iirc) followed by constant aftershocks over the next few days. that got my attention and i am glad i stocked up on water and canned goods. after the huge one hit on march 11th, the supermarkets basically went empty for a week.

it was an interesting study in efficient logistics systems - i learned that certain industries really have their stuff together all the time and can just keep on ticking, others like supermarkets break down quick. getting food was sketchy business for a while.

just my advice. the phenomenon of a big quake followed by constant aftershocks before the main megathrust occurs is very well documented, you can observe it in many of the largest recorded earthquakes.