Time It Takes For Gums To Recede

Can gums recede in as little as 2 weeks to 2 months from around 1 crown only and not the surrounding  teeth?
There is a crown on one side of this particular crown and a regular tooth on the other where the gums are unaffected.
I did not think the problem crown was placed high enough when first put in. My dental floss got stuck every time I tried to floss so the dentist replaced the crown at his own expense and the next one was a little higher up. For almost the first week I tried not to floss up there, I think. But after I started flossing normally I could feel the edge barely catching there, but catching just the same.  This crown was replacing the one he put on in 2007. My floss had started catching on the inside between 2 teeth in 2008 and breaking in 2009. He did an xray and said there was decay and infection eating my tooth but I couldnt afford to get it dont til Dec 2010. He put a temporary on but never did an impression in dec. In Jan the first crown that was too low and my floss got stuck in was put on. In March the second one was put on. I didnt say anything til June about this one and he said my gums have receded and asked if I eat lemons or have a lot of gastric juices that might I dont know, eat my gums??I said "No". So I'm asking, "How long does it take for gums to recede, and what might be the cause"?  I will be discussing financial liability for this third rendering of the crown or going elsewhere and paying cash. I would appreciate anyone's educated experience in the matter.