Hi,
Does it matter if the solder on the 5V regulator is touching both the ground and power because both solder bubbles kind of merged together?
You bet it does!
That would create a short and possibly fry the regulator and micro-controller.
Please tell me you didn't have the ATmega plugged in...
Nothing would get fried except perhaps the power source and the wiring/traces involved.
It's a dead short, so no power will get to the controller (or the regulator, but it may have been killed while building up the solder bridge).
kser <- I am a bit shaken, that anyone could ask such a question! Did you think that schematics and such were just made as a suggestion/recommendation that could be followed or not - what you did was the same as shorting your battery (or PSU) with a screwdriver.
We have all made short circuits at some time... But asking if it matters
The number one source of errors for beginners is poor soldering, find an old/discarded piece of PCB, study how the solder joints looks and practice removing the solder and resolder until you are through "blobbing" and start making good joints.
Next thing, get a magnifying lens and examine your work carefully a couple of times under lots of light.
You need...
1 Solder Sucker
1 Reel of Desoldering Braid
1 Magnifying Lens (x4 to x10)
1 cup of patience
2 ounces of determinism
1 Aloe Vera plant (for when you splatter solder on your skin)
Stir under medium heat (~700-800°F) if using leaded solder, a bit higher if you use the unleaded variety.