Well, that's good news.
I did get a similar response though to mine. Did it on a Sunday, went into the doctor Monday morning. The person I saw wanted to send me home and schedule the MRI for a week later. HA! I knew there was something significantly wrong with it and asked to be referred immediately to an orthopedic doctor. Had the MRI that same day and the next day found out the results (completely torn ACL and MCL).
I had to fight with the first doc to get that referral to - she was hell-bent on sending me home with directions to ice it and try to stay off it. Crazy...seeing how it was clear something was significantly wrong.
Yours does not sound near that significant. However, if it's not getting noticeably better within the next day or two - get back in there and get an MRI done.
As for the cost, you have insurance (I assume) so they'd pick that bill up...or at least most of it.