I am a permanent resident and I noticed my Brazilian passport does not have an entry stamp when I came back from Brazil from a vacation trip. The US immigration officer did not stamp my passport upon entry into Miami Int’l Airport. Now I am applying for my citizenship and I am afraid that his could be an issue. So in the last 5 years I had 8 trips but I have only 7 entry stamps on my passport. The only document that I have is my eletronic ticket from this trip. So... what should I do before I send my Form N-400 Application for Naturalization ? Thanks !