saypoint, I'm not sure about the medical implications, but I do think it could be worth a call to your doctor if you are still coughing and/or it is difficult to breathe.

I have not had this experience with leaf mulch, but I have twice (!!) stupidly forgotten to wear a mask while sanding joint compound on my walls. Both times I ended up with a severe case of bronchitis that lasted a long, long time. But sanded joint compound has much finer particles than what you aspirated, so hopefully that won't be your experience. In any case, I would call the doctor and ask for his/her advice.

Don't mean to sound like an alarmist but it is possible (not inevitable) for such a foreign object to cause a severe lung infection. I would definitely call your doctor and watch yourself for any symptoms.