Just remember that even if you do pay the bill now, it will still show up as a negative on your credit report for some time to come. After you pay it, you may need to contact the company and respectfully request that they no longer report the account to the credit bureaus. If they refuse to stop reporting the info, write a short note explaining the circumstances and send it to the credit bureaus to be added to your credit file. It will help potential creditors in their decision to offer you credit.
It's true that a negative can be reported anytime, even years later. Most of the time, though, it's 7 years or less from the last date of activity on the account.
I wish you the best...Janna