Couple of good tips for watering -
One, use your smallest finger (hopefully your pinky, lol) and push it knuckle deep around the very edge of the pot to feel if the soil is moist that deep - if it's moist that deep - don't water.
When you do your first watering, feel the cup, pick it up - feel the weight. Do this with your bucket too, this is now your "fully watered weight", feel it every day and do the knuckle test. Once your knuckle is dry this is your "close to dry weight", let it go usually one more day UNLESS the plant droops.
Underwatering is MUCH easier fixed and has less adverse effects than overwatering. Especially a seedling.. overwatering can cause damping off, the seedling to stunt and give home to fungus gnats.
So, check your cup, how is it? I usually just use a spritz bottle for seedlings and spritz 2-3 spritz (it's not a lot, you want to keep it "kind of damp" not "wet" and not "moist" but "kind of damp".)
If you water too much, the seedling won't search for water and form a stronger root system..