If I were you, I probably wouldn't worry about no response after three months unless I got to three months with no response.  But that's just me. 

FWIW, most people who've gone over the standard dose have waited longer than three months.  I'm not saying this is a good idea -- I'm pretty sure we should see 
some results by the three-month mark -- but that is what a lot of people do.
You haven't been doing this that long.  Maybe just give it a whirl and see how it goes?  You might turn out to be a fast responder and not even have to think about this issue.