I have a few questions about miscarriage, will someone help please?

How easy is it to do something physical to cause a miscarriage? I'm 11 weeks and 3 days pregnant with my husband and i's first child we planned the babyand february and got a positive test basically immediately, I was a very active person before the pregnancy like playing with dogs, I did work construction, playing with kids, I've calmed down a lot since I found out I was pregnant but every now and then I do something I feel like I shouldn't do then it worries me, like- plopping down on the couch to hard, kneeling down on the floor to fast to play with a kitten, its minor (hopefully) stuff like that-that worries me, I apologize if I sound like a worry bug and my questions don't make sense but id really like to know if its easy stuff like that for example that could cause a miscarriage? Can someone please help me?