At 2 weeks it should be a bit bigger that it is, you should be ready to move it into a larger pot. Your soil looks really wet, dont over water. Did you make holes in the bottom of the solo cup for drainage and so air can get to the roots. Is this just a random bag seed are good known genetics? My guess is you are over watering it, let the soil dry out before you water. You should only need to water a solo cup every 2-3 days.
Your seedling looked like mine as i planted mine in a 1 gallon pit that's where i went wrong as the seedling grows the roots first the produces the plant's leafs.
would tansplant it, ONLY so you canredo the soil, est the ph runoff, make sure its around 6.5 for soil, give it the lowest nutrient dose to the directions, for a seedling, put the other bul back in there, prop the plant up closer to the lights, leave them on 24 hours, when you transplant, ONLY moisten the soil, but test the ph before you plant it, then after until its dialed in, dont EVER mix the nutes togethr, LOCKOUT, but fr now ffof with water, dont kill it yet!!!!