Damn, man...sorry to hear that.
I've never been in your situation, but I have known several PT's & PTA's over the years.
The beginning stages of rehab are very similar for most patients, and a good therapist should be able to adjust your therapy according to your progress.
However, even then, their rehab may be inadequate for you beyond a certain point.
The severity of your procedure, recovery ability, and the kind of shape you were in prior, all make rehab progress a very individual thing.
In some respects, nobody knows your body better than you.
If you feel you're ready, start, but start back slow, light, and use plenty of caution.
Wish you the best, brother!