I agree with all above that dbol needs to be ran 4-5 weeks. For me, 4 weeks is perfect. I see the gains I like and I can stop before the bloating and lower back pumps get unbearable, which for me occurs in week 5.
As far as timing, I like to do something like what you are contemplating. I like my jump start in weeks 1-4, so that I have an anabolic foundation while waiting for my injectables to kick in. Then, I'll start Dbol during my last week of my injectables, and run it until about 4 weeks after my last shot. Then I just roll right into PCT.
I really can't say much about using Dbol in the middle of your cycle, except that with long ester injectables like Test Enthan or Cyp, EQ or Deca, it is always later than you think. Three weeks after your last shot the stuff is still prevalent at an effective level in your blood, so if you do it my way, you are running your Dbol in the middle, to some degree.
Either way you go, keep us posted.