Of course not. Use the professors in your department as the valuable resource that they are. All of us have experience in helping our students make decisions about graduate school. You will have your own unique questions and concerns. Even after you enter grad school, there may be things that we can help you with.
Most professors really enjoy hearing from their former students who are now in graduate studies.
It's a wonderful validation of the work that we do, and it's very fun to watch a former student become a colleague in science.