Icloud backup

So my iphone photostream is full apparently......normally i would just back up onto my harddrive and Icloud. However for some reason my photos that come up when i plug into my laptop are not all the photos on my photostream. So what i want to know is can i get my photos off of icloud to save elsewhere? And if i delete the photos of my phone will they also be deleted off my icloud? Many thanks for your help