Where Do Cloverfield Monsters Come From?

If you haven't seen Cloverfield, than read no further as we're about to enter spoiler territory.

Where did the Cloverfield Monster come from? Japan? The ocean near an offshore drilling site (as hinted by the viral)? Not so according to director Matt Reeves, who supposedly told Film School Rejects that an easter egg within the film tells of the Monster's origins. Apparently in the background of the footage that HUD had taped over, when Rob and Beth were at Coney Island, "something suspicious" drops into the water.

While I very much believe this subtle easter egg is probably in the film's final cut, I just don't buy the reasoning. Beth and Rob's trip to Coney Island took place in late April, but the monster waited a full month until late May to destroy New York City? Doesn't sound too logical, especially considering the whole Tagruato viral storyline which was to set up the monster's origins. But I could be missing something.