I had an accident like yours about this time last year. I hadn't been on the bike for more than a mile and was about to go onto a 2" curb into a driveway. Wham! I went down so hard and fast that I just layed there for a minute wondering what happened. I had plenty of road rash down one side, but after a few days it became difficult to raise the arm that I fell on. I went to the doctor who told me I had strained what he called the 'slingshot' muscle that goes from about the shoulder blade, over the shoulder and into the arm. There wasn't anything that could be done about it and he told me it would take 6 months to heal. It took about 9 months.

So yes, I agree with others that you should see a doctor... sometimes it takes a few days before the injuries show themselves.

Cheers!
Linda