I have extended a few times at the last minute (it is always so hard to come back). One time I was on antibiotics that were prescribed to me in JA and gave American Airlines a note from the doctor--I could have flown, sure--but there were documented "complications" I was having with the meds which granted me a few more days till travel and free ticket change. Other time I paid 125 to change flights and stay 3 more days--totally worth it IMO. But I did gain a bit of a reputation at work and brows furrowed when I said I was going to Jamaica (yet again)--coworkers wondered when and if I would come back.