Never been to stamping since 2004 ?


I came to US on f1 visa in 2004 to pursue the MS degree and never been to India since then. I’m currently in 5th year of my H1B visa . I’m planning to go to Vancouver for my H1B stamping and wanted to know if there will be any problem ? I have all the documents to prove my legal status since my arrival to US. What should I answer if the visa officer asks me why I did not go for visa stamping since 2004 ? I’m in a dilemma, please help me as soon as possible.