Sometimes they start out on a low dose to see how you tolerate it, then increase it to the dose that works for your needs. All depends on what's going no with you.
Just be completely honest and report any odd or unpleasant reactions. Remember, you're a team ... You aren't a lab rat. You and your doctor are equals, and the goal is the best possible meds for you--not just something that's "good enough" to get by.
Relax. It's going to be fine.
roadie