Identify the precise fear. Then, ask yourself if its driven by fact or fiction. I wrote a blog post about this recently on my personally blog (links in signature). But cant link it from my phone.
Definitely no set timeframe. In fact, first two woman dh was with I was ok and resolved any insecurities in a matter of hours. The last-led to near hospitalization for severe anxiety attacks.
Every situation differs and you have to deal with them individually because the emotions could be based on a legitimate risk or on an untealistic fear.
"Love As Thou Wilt"