I, too, have been cut twice in the last two and a half years, most recently in the right knee December 18. (I'm 40). The biggest thing was that each knee healed differently: the first time, I ran 16 days out of surgery, ran a pedestrian 5k four weeks out, with each mile progressively faster, and really had no issues but letting the swelling dissipate after a month or two or three...
This time, I had horrible calf pain (apparently not blood clot related, though the bonehead surgeon couldn't have cared less!) for a week after surgery, and still stop while running to massage my calf. Last weekend I ran a tough 7+ miler on trails (BTW, I have hardly run on pavement since surgery, sticking to tracks and trails). Looking back at my log, I find that I've always had trouble with my right calf, going through periods of fairly intense tightness every year. I never paid much attention to it, and now I see the pain was always in the same leg. Anyway, I ran a 5k last weekend, too, working hard to jog a seven-minute mile to begin, then 6:56, 6:42, all the while making sure I was JOGGING, not running. In many ways, it was fun to trot along with folks working real hard--it's quite the ego boost.
My last point is that you should just go with it. You're not having anything reconstructed, so as my physical therapist said, you'll have no more risk of tearing something than the average joe. Pay attention to pain and fatigue, and don't try to run through it, as you would when you're heatlthy. We have many, many more miles to run, so six weeks of "wimpiness" will only help...