I have pneumonia

This is the first time I've ever had pneumonia and I don't know what to expect. How long does this last? I really need to get back to work and the gym. Has anyone else had it? I have been sick for about 3 days now- thought it was a bad cold until I went to the doctor yesterday and got X-rays and they said it was pneumonia. I haven't even been out of bed except to go to bathroom and doctor. I have to go pick up my prescription antibiotics before the pharmacy closes in a few hours and I am really dreading getting out.