Your workflow is simply crooked. Nobody would work this way. Track everything first and then do whatever adjustments you need to do later.
You can pick up from where you left off on a track. You just select the tracker that you used originally rather than clicking the button to start a new track.
However, Mylenium is right. Your workflow is odd. Edit in your NLE (Premiere, Final Cut, etc.) so you know what pieces of a shot you'll need. Then track it all before you do any further work.
If you select the layer you are tracking and press the U key you can see the keyframes that the tracker generates. Go past the last keyframe with the CTI and then press the j key. Now you are positioned at the last tracked frame. Select the layer as the tracking source and continue.
I agree with the others, your workflow is flawed and very inefficient.