Stretching is an art form that is fulfilling and exuberating when one takes the proper planning and precautions. Patience and preparation will minimize injuries and infection due to overexertion. Blow outs is an injury that I've seen happen to many enthusiasts. It's a nasty thing that is painful, dangerous, and counter productive towards your path to the final size. A blow out happens when the amount of pressure you are enforcing against your stretched lobe is more than the amount of elasticity the ears can currently take. The excess pressure from the point of insertion causes the skin from the inside of your piercing to flip in and out. Stretching too fast and skipping sizes is the main reason to why blow outs occur. Not massaging and lubricating your ears properly can also cause this nasty problem.
How to fix a blow out?
Downsizing is the proper way to let your lobe just chill out for a second without any attempts to go back up in size. A few sizes down might be necessary to make sure that it can heal as best as possible to minimize scar tissue. Also clean it a tiny dab of water with antibacterial & unscented soap when you see puss and blood starting to leak out. Keep an eye on it and wait a few months before even thinking about going up a size. Harming yourself during stretching is counter productive. Slow and steady wins every time.