Question about naming my business

I am filing Sole Proprietor. Do I have to check on availability of the name I chose? I looked online and theirs only one active acct with the same name, but it's under LLC.Is there anywhere that I may be able to find out even after hours and weekends? I really don't want to wait until Monday to find out if I can choose this name. I wanted to get everything worked out this weekend as far as business cards, email acct for the shop...etc. Thanks for any advice.