So close… But a huge improvement!

My journey to Boston continues… I ran the Mountains to Beach marathon in 3:52:16 a huge improvement from my 4:13 at the LA marathon but still 7 minutes shy of the needed 3:45 to qualify! Ugh!!! While I am disappointed.. at the same time I am quite impressed with my 21ish minute time improvement!
There is always another marathon right!??
In fact, I am already scouting out my next race. I found a handy website which lists all the fast Boston qualifying marathons, complete with stats.. Interested? Here is the link.
Fastest Qualifying Marathons
Sooo.. The question is how long should I wait before I give it another shot?