Start learning the weight after you water. Wait for top 1/2-1" (~2.5cm) to dry before watering again. If soil, you fertilize differently than in coco. Either way, remember a tiny plant can't drink much. So, fertilizng too often early causes a build up.
Before i say, I do the same thing. However, it's not the best-sized pot for that sized plant. Substrate matters a bit too. Also, if it's an autoflower it could be wise to avoid a transplant etc etc.. but in general larger pot is more difficult to manage with a smaller plant.
You won't be able to saturate the soil without waterlogging the plant a bit. Coco isn't as bad, but still stays wet longer than you'd like while large portions of the volume being completely unused by the plant and 100% evaporation and buildup of nutrients and hard water occurring.
so, before doing what was said above, i'd fertilize occasionally near it, but only keep the outer areas hydrated enough not to repel water if it gets bone dry. Difficult to say exactly how to ramp up. I'd base it on the size of the canopy and past experiences.
If the leaves stay droopey and everything else seems okay, try raising the lights a bit. Yougner plants need a bit less light. this sort of stuff you are better off reacting to... make certain you know the cause of any problem before doing anything.
It'll be a much more robust plant in a week. Likely grow out of anything it is showing within reason.