I can almost guarntee you that she is pregnant now, rabbits don't have a heat cycle and can get pregnant at any time, you now have alot of preparation ahead of you, it only takes 31 days for a female rabbit to give birth.
First step is to decide whether you want her to have babies of not, if not, then bring her down to the vet and get her spayed ASAP. If you do want her to have them, then it's time to start getting ready.
First, you need to buy a new cage for the female rabbit, you can't leave her to have the babies in with the male, because she will kill and eat the babies due to stress, and it's not nice to find bits of babies all over the cage.
At 28 days, you need to give her a box to have her kits in, a large shoebox will do, it needs to be big enough for her to be able to turn around fully. Put loads of hay in the box and leave it in her cage.
Sometimes straight away the mother will start to pull out her fur and use to make a nest in the box for her babies, she will rearrange the hay and fur to the way she wants it, and you should leave it that way. Some mothers don't pull fur until right before the babies are born or right after.
Around day 31 she should have the babies, it is usually during the early hours of the morning, if you walk in on momma giving birth don't stay there, leave her alone, she could get very stressed if you are there.
A couple of hours after they are born have a quick peek in the nest and take out any dead babies or uneaten after birth. Make sure to cover the babies back up.
24 hours later, check each baby one by one, check their bellies, if their bellies are nice and round then the mother is feeding them, if their bellies are sunken and wrinkly then she isn't feeding them, consult your vet.
You will probably never see the mother rabbit with her babies, they totally ignore them till feeding time, then they just stand over them and feed them then hop out again. You will probably never see her feeding them.
Check the babies every 24 hours to make sure they are developing, remove the dead ones through the process.