Give them three days before you worry. Are they on nutes yet? I'm guessing no but if so, no nutes until they recover from the stress of transplanting. Same goes when you put them into the three gallon pots. I'm thinking they can go to at least 12" before they need to go into the three gallon pots. They should have plenty of room to stretch their roots now, and you want them to have some root room through flower in the new pots. Some people have recommended burying the step 1/4 - 1/2 inch during any transplant. I have not tried this myself though.