If you are being sued, how long....???

There's no telling how long it would take. It could be that they are just calling your bluff to get you to pay, they really aren't sending the papers. If they are or did send them, the court would need time to process them and set a court date and notify you.

So how long could that take. Is it days, weeks, month or does it just greatly vary??

I guess it would vary..I would assume you're ok for a few weeks at least. Just make sure you answer the summons if and when it comes. Otherwise you may find yourself with a default judgement. Seriously, contact the creditor and try to make arrangements now if you honestly owe this debt.

Nowadays, most courts have their own website, where you can check the status/history of cases online. If your county court has a webiste, just go plug your name into the search box. (I actually found out this way that a case was filed against me before).

Usually, once a case is filed, the return/answer date for the summons is about 30 days later. At least in IL, they need to serve you at least 3 full days before the court date; otherwise, you aren't counted as having been properly served.