I had an odd experience, I was doing my meditation as usual with Candles of each color. But suddenly the flames grew so long, they were about 10cm in height. Never happened Before so I'm still quite impressed, is there perhaps negative energy or is it simply the Power in the air tonight?
probably the energy of the 100% full moon. it was also Valentines and some people view it as an important day. what colour was the candle? if it was pink or red then i would agree it was energy surrounding the day.
could also be a draft. say the candles were in a circle around you and someone opened a door in another part of your house, if your door was open a crack, it would be enough to move the door, creating a sudden draft of air.
i use to have a similar experience when circle casting with my coven. one of the older members was a very energetic leo, when she cast the circle the fire candle would always burn down the quickest. depending on if you use the candles in a spell, protection, or the elements when you meditate, you could of placed more energy into that one unknowingly.
if it was a negative force, you should of felt something else, such as the room was colder by that candle, or the energy was heavy.