My penis grew 1.5" in 2 weeks is that at an unhealthy rate?
My penis (how original)
"This is not my life
It's just a fond farewell to a friend-"
if you're undergoing puberty thats perfectly normal, but if you're not then yes I guess it is
It could be considered uberhealthy.
It's very unlikely that any growth rate like that could continue for any length of time. In fact, I'd suggest that most of it would have to be a measurement artifact. Some people have "stretchier" penises than others, and for them the measured apparent erect length can depend a lot on how horny they are at the time. So if you are much hornier and harder the second time you measure than the first, the length seems to have grown a lot.
Like Inelegible said, it is very unlikely that your penis grew that much in 2 weeks. Impossible. But as was said, the penis is like a big stretchy spongy balloon. You were probably extra horney and the penis filled with extra blood which stretched it to the max.