Small mushrooms in pot??

Ok guys quick newb question,

I have my plants in about 1 month veg period, and i just recently noticed that alot of the leaves on my one plant turning a yellowish color. I also just discovered about 15 small very small 'mushroom' looking plants growing around the perimeter of my pot. does anyone know why, or how?? i am using MG Organic soil.

Thanks guys! i need help!

im quite sure that its the circulation. are there enough vents, and how far away are the lights to the soil?

ALOHA

they are decently dar away from soil, like 1 foot. and there is no vent, just a fan.

I would think it's some kind of mold. No ventilation would cause wet, stale air to build up.