Hi there. No need to be scared because what you did was a no risk situation for being infected with Hepatitis C. There are a number of reasons why:
1. You have no idea if he even had Hepatitis C. I'm guessing you're from Hong Kong with the "HK" in your username. Only about 0.5% of people in Hong Kong have Hepatitis C. So right off the bat, there is a 99.5% chance that there is no Hep C even in the equation.
2. There has never been a documented case of kissing being the cause of a Hepatitis C infection. It needs to be blood-to-bloodstream. Wounds in the mouth heal very quickly due to a protein that is in saliva. Scientists are actually working on synthesizing it so it can be used to help heal wounds in other parts of the body. Chances of him having a bleeding cut in his mouth are very small. Even if he had any blood in his mouth and it was transferred to your mouth, your saliva and anything you drank would wash it out of your mouth, down into your stomach where the stomach acid would destroy it.
3. When you brushed your teeth, there was no Hepatitis C in your mouth (see #2). Also, when you bleed, the blood is flowing out, not in. Think of it like a hole in a pipe - the water coming out of the pipe washes away anything that gets near the hole.
4. An encouraging statistic is that medical personnel who are working on a patient who is positive for Hepatitis C and accidentally stick themselves with a bloody needle only get infected at a rate of around 2%. Hospitals maintain accurate records of this and anyone who suffers a needle stick must report it to the hospital staff for liability reasons, so the numbers are dependable. Kissing a guy isn't even close to a bloody needlestick, so taking in the other factors above into consideration, the chances of you becoming infected with Hepatitis C are so small, they are incalculable.
No need to get tested for this, by either the standard antibody test or the DNA PCR test. Just to answer your questions, the windows period for the antibody test is 3 months and the DNA PCR test is 2-3 weeks. Again, no need to get tested here. Have a few less drinks when you go out and avoid making out with strange guys - sometimes that leads to more than kissing and a whole bunch of other problems.