I met a man at a rabbit show a while back, who was telling me about his start in rabbits. " I had two of them," he said. "After a year, guess how many I had!" Knowing how rabbits can be, I wouldn't guess, in spite of his repeated encouragement to do so. Finally, he told me. "One," he said. "The other one died!" "Yep, they'll do that!"
Maybe you have to be a rabbit person to understand just how frustrating they can be.
As chinbunny said, this isn't the best time of year to try to breed. With the long nights and cool temperatures, some does just aren't receptive. Mounting behavior can be the result of simple excitement or a dominance thing, I wouldn't attach too much importance to a doe mounting anything.
I haven't ever tried the "forced breeding" technique that texasgal mentioned. I know people that have, and they said the doe frequently didn't conceive when they did it, so it wasn't something they continued to do. Most of the rabbit breeders I know prefer to let the doe tell them when she is ready to breed. I always check a doe before I take her to a buck. You turn the doe over, and evert her vulva a little (like you do when you are trying to sex a rabbit). The color you want to see is a bright, cherry red. The lips of the vulva will be slightly swollen, as well. Some does never get darker than a sort of rose color, so you need to know your doe. If the vulva is pale pink, don't bother, she probably won't breed, and most likely won't conceive if she does. If you see a sort of purplish color, the doe has passed her hormonal peak. She may breed (and even conceive) on this color, but it's less likely. Give her a few days, and check again.
I have one doe that will fight the buck at first, even when she's showing red. As long as nobunny's getting hurt, I leave them be. I guess she just has to make sure he's tough enough, because she will breed after a bit, and conceive a nice litter. Like I said, you have to know your doe.
Taraann81, your guess is as good as mine as to whether your lionhead is pregnant or not. Rabbits do a 28 day cycle (sort of). Does hit one of their highest hormonal peaks at the time of kindling, so she may be receptive and about to kindle at the same time. I would certainly note down the date, as she may have gotten pregnant from that breeding. Rabbits have a y-shaped uterus, with each horn committed to the eggs from the ovary on that side. Rabbits are "induced ovulators", which means that they ripen eggs, holding them in readiness until the act of mating causes them to be released. It is entirely possible for a rabbit to be pregnant only on one side, be mated at a later date, "fire" on the other side with that second mating, and be carrying two entirely separate pregnancies with two different due dates!