When a buck "does the deed," he grabs a mouthful of the doe's fur on her shoulders, and makes rapid thrusting movements with his pelvis. When he actually is successful, he gives one big thrust, usually grunts a couple of times or maybe squeals, and falls over to one side, sometimes taking the doe with him but usually pulling out the mouthful of fur in the process. On occasion, a young buck may go though all of this without actual penetration taking place.
When you flip a rabbit over, there is a fuzzy bump "back there." Are you seeing little sacs on either side of that bump, or just bare patches?
Yes, they ALL 4 have sacks
We rabbit people often joke about getting visited by the "sex change fairy," but that is in younger rabbits. By the time a rabbit is old enough to breed, there should be no doubt about what gender it is.