Here's the deal. You will NOT be allowed to ride outdoors or with cleats for some time. My PT is also an avid cyclist who blew her ACL the week before mine, so we went through rehab together (well, kinda -- at least she was in the same boat). She knew that my goal was to be able to ride the Bicycle Tour of Colorado at the end of June; my surgery was in mid-March. I didn't make that goal. In fact, I wasn't allowed to ride outdoors until the 3rd week of April, and then only with platform pedals. I was not allowed to use clips before the beginning of June.
That being said, I did a lot of training on the stationary bike. I was on the stationary bike 4 days after surgery. Of course, they wanted the power output pretty middling, and only 20 minutes to start. I built about 5 minutes a workout, and was up to an hour after about 2.5 weeks. The key thing here is not to overdo it. I was constantly riding the line between overdoing it (resulting in swelling) and just enough.
At 6 weeks, I was able to start riding outdoors. At 10 weeks, I rode my first metric century. I wasn't able to ride beyond that (and probably shouldn't have done it in the first place) as I was getting a fair amount of swelling.
You just have to play it by ear and, most importantly, listen to your body. Don't overdo it. You can crash and destroy the surgery. The ACL is weakest 3 months after surgery. And setting yourself back by getting the knee inflamed just means that your recovery is delayed.
It will come. Patience.