If he fell off and twitched and stomped after "attempting", that means that she was bred. ( I find it funny every time,..just cracks me up, they are just too cute not to laugh)
I generally try to have him do his business 2-3 more times during that first phase/meeting. If I only get 1 mating out of the first time or if I want to be sure she is bred for sure, I go back 10-12 hours and let him do his business again. You can go back tonight and have them mate again, but that would be the last time.
They ovulate 10 hours after a mating.
A lot of people just let them do their thing 1 time. I personally find that it is better to do it this way. Some does will stand for a mating and will not ovulate. The odds of multiples have not increased for the multiple matings. You don't want to breed them any further though than that second mating at 10-12 hours later. Rabbits have 2 horns,...so with rabbits it is possible for her to have 2 different due dates,..
Some people palpitate, I find 30 days a short time, so I just set them up in their "momma" cage 3-5 days before they are due and see if she delivers.
From my experience, if you get 3-5 matings, chances are, she is pregnant unless the situation was extremely forced....
What are you outside temps right now? If it's pretty warm, the buck could be a little less fertile.....