Ok, if this is a dumb question, please be gentle!
I got my 99k all cleaned up, oiled, and it seemed to be running like a champ. Well, to impress my husband with my handy work, I whip out a piece of denim to show him how beautifully this machine runs after a good clean. Of course, in my cockiness, it won't sew!

Upon further inspection, the bobbin is not working. It won't pull up with the needle, and even if manually pulled up through, will not do anything. Any thoughts on what might be wrong? If so, how do I fix this?
When I get home, I can post pics to help clarify things if needed.
Thanks in advance!