Is it for recurrent? There is a side letter on that which opens up the window of acceptable travel dates, to include subsequent bid month.
If its not training...pretty sure the 3 days is hard and fast. CE is probably worth a quick email.
On another note, I returned from states on company ticket (not recurrent) and was quite sick the day after I landed with a stomach bug. Simply no way I could fly a trip two days later, a short 2 leg HAN-SGN trip. Called in sick. No choice, but that was a $3100 ticket I will eat for that virus.