Help

So im new to this and I just was wondering if someone can tell me why my plant is droopy it 3 weeks old it some true OG I got it as A clone but I really didn't know what I was doing so I went to lows and got this miraclegrow soil that already has 6 months of food in it for house plants so I thought that would be good but it was doing good all the way tell today I notice that it was looking a little droopy so can someone help me out oh I have it under A 400 watt hps light

First off never use miracle grow, the nutrients in it are definitely not tailored to growing marijuana. Besides that it sound like your plants are either underwatered or overwatered. Most likely its an overwatering issue as thats one of the most common mistakes. Your girls need much less water than you would think. I have a few nearly mature plants in one gallon pots and they only get a 1/6 of a gallon every other day. The plants I have in 7 gallon pots get a gallon of water once a week and they could still go another couple days without much stress. To check your soil to see if its ready for water just stick your finger about an inch or two below the soil surface and if the soil is moist and sticks together dont water, if its dry and crumbly give it a drink. Other than that high temperatures can make a plant droop but its hard to asses without a picture of your plant and your grow specs (temp, lighting, vent, nutrients, environment, ect). Hopefully this helped, but if not post a pic and you'll get way more help from other RUI members. Good luck!