it is not that they "will" take you cert back, but they definitely could!
Talk with your POI. If you have a good one and an understanding one, you may be able to get more time--- it is not unheard of to exceed the times and it is at the discretion of the POI at that point... however, if you exceed the time and get more time from the POI, you are now on borrowed time and at any minute if the POI feels lack of movement in the right direction, he/she can seize the certificate at any time.