You can take a sample for informational purposes, but I'd let it sit for another week at least, no matter what your reading turns out to be. The time gives the yeast a chance to mop up and fall out and settle properly. You will have much better beer and bottling will go so much better just for giving it that extra week.
If you really want to brew another batch now, can you get another primary (food-grade bucket)? Lowe's sells them pretty cheap, with lids.