The 68-year-old admitted she had ignored doctor's orders to rest before she 'overheated' and felt faint at the 9/11 service in New York. Asked when she will return to campaigning, Clinton told CNN: "Well, it will be in the next couple of days.
"I just want to get this over and done with and get back on the trail as soon as possible.
"I just didn't think it was going to be that big a deal."
The Clinton campaign acknowledged it may have been too slow disclosing her pneumonia diagnosis. She was diagnosed with the lung infection on Friday.
Clinton spokesman Brian Fallon told MSNBC: "I think that in retrospect, we could have handled it better in terms of providing more information more quickly." Earlier on Monday, Clinton took to Twitter to assure her millions of followers she was OK.
"Thanks to everyone who’s reached out with well wishes! I’m feeling fine and getting better.