Overwattering ? Yellow leaves and hanging a bit

Yeah. I don't believe that is anything to do with overwatering if your only watering every 2 to 3 days. It looks like they are pulling nutrients (mainly nitrogen) and food stored in the bottom fan leaves. During flower when the buds start to really fatten up, the plant is using a shit ton of nutrients to support those buds, so if there is no more nutrients left in the the soil for the plant to uptake and use, it will start pulling the nutrients and food stored in its fan leaves. Thats what causes the bottom leaves to strart yellowing and dying off. It is natural for the cannabis plant to use and dispose of its bottom leaves. If you are close to harvest, this is what you want to have happen during the last two weeks of flower. You want the plant to pull all of the food stored in its fan leaves before you harvest to get a nice flushed smoke. They leaves will yellow and die during that 2 weeks, and depending on the strain your growing, the leaves will change different colors (purple, red, yellow, orange, ect.)