Yeast is an interesting creature. I just did a blueberry ale with liquid yeast and had zero signs of fermentation for 72 hours. I ordered California Ale V from AHS as a backup in case i killed my yeast and before it got here it started bubbling away. Now a week later i hit my FG and it's all good. I've heard people on this board say to give it 72 hours and even then, don't worry about it. Just correct it.
If you were using dry and/or liquid yeast you can just buy a second serving and pitch it directly into the carboy (with proper sanitation).
Primary : Nada
Secondary Edwort's Apfelwein, AHS Titannia Wheat On Deck: LHBS IPA [Recipe Unknown], Corona Clone (Lawnmower Beer)
Bottled: Spicy Orange Pale Ale, Stone Cold Brown Ale Kegged: Spicy Pumpkin Ale
"When I read about the evils of drinking, I gave up reading"