Is my rabbit pregnant?

Well, basically. She started making a nest. But i didn't know what making a nest ment. So i cleaned her out, and she started making a new one straight away. Her belly feels a bit hard on the edge, i didn't touch it too much incase i did something wrong. Shes quite fat too. I've only had her 2 weeks. And the person before me had 5/6 rabbits. Do you think she is pregnant? If so how long will it take ? What do you recommend ? Or do you think it could be a flase pregnancy.