I actually agree with Don, but I also think the original post lacks a few key pieces of information, specifically what type of position and company this is.
Cass, moving forward, I would give the hiring manager 1 1/2 - 2 weeks minimum before "following up" for Don's reason: they probably haven't had time to look at your application. Think about it. You applied on Wednesday. It went into a pile with other resumes. Depending on the size of the company and how urgent they are for new staff, they may look through the new applications once a week, once every other week. Thurs - Fri - MONDAY. You only called 3 business days later.
I wonder if this is a customer service position since you mention "stopping in", but I would think that even if so, Fri-Sat-Sun would be their busier days and no one would have time to look at your resume. (Note: If it is not a restaurant/retail store, I would advice against stopping in ever, and if you do stop in, I would do so while dining/shopping, then mention, "Hey, I applied her a couple weeks ago and it seems like a great place to work. I was wondering if you are still hiring" very casually).