Unless this is an "auto," always start them out in something small...like Solo cups. It takes much less time for the root formation to happen and the foliage to start growing. Putting a tiny plant in a large pot like that (...ALWAYS FILL POTS FULL!!), will make it take longer to get rooted in so don't think nothing is happening with it. Do not give water or nutes because you think it should be doing more. Give it the light it needs and only properly pH'd water (range is 6.3 to 6.7)...if you want it to stay healthy. Watering or feeding with water out of range will lock the roots up on your plant, so pH is a big deal. They need defined wet/dry cycles too, so don't water until your plant is at least 80-90% dry. If the pot doesn't feel as light as it did when you filled it with dry soil, it's not time to water. Having your roots sitting in moisture all the time is no good for the plant. If you've got it in good formulated grow soil, you pH the water to the right range and you water correctly....basically don't over water, your plant will do fine during the veg stage. It will be ready to up pot when it is as tall and wide as the container it is in. Good luck! TWW
i do the same thing and fill cups halfway with dirt until stretch is over and first bladed leaves emerge. but now that yours has, you should go fill that cup up until about an inch below the first set of leaves or it will get too heavy and fall over,,done that too. good luck