Did you get the suboxone from a doctor? If so, he should have told you when to take the suboxone. Many times they'll have you take it at the office so they can see how you do. You have to be very careful with suboxone. If you take it while you have a narcotic in your system, you can wind up in precipitated withdrawals, which, from what I understand, is way worse than regular withdrawals. And there's no way to get out of it once you're in it.
I don't have the link but if you google "COWS scale" you should be able to find it. It will list the criteria you should meet before taking suboxone. I believe you have to be in moderate to severe withdrawals before taking the sub. It will give you a list of the withdrawal symptoms you should be experiencing before starting the sub. Please look it up so you can be in the right place to take it.
Suboxone is supposed to be part of a program. It's not supposed to be just about taking a pill to avoid withdrawal. It's a serious medication, and it needs to be taken properly. It's concerning that your doctor didn't go over everything with you in detail. The fact that you're still taking hydrocodone, even at the low dose you're at, means you should not start the sub. You need to be totally off it before starting.
Please call your doctor to get the correct information. Let us know how it's going and what your doctor suggested.
Too add to the above post, out of curiosity, how much did they tell you to take daily?
I waited 12 hours after my last 10mg perc when I dropped down before I got on suboxone. Its usually 12-24 hours after a barbituate or instant release opiate. As for things that are time release like oxys, ms contin, ect, its a longer wait. They tell you to wait until your in full blown withdrawal because that is when it works best and depending on what your DOC is you can go into immediate day 3-4 withdrawals which *****.