I think that if you are saved then Satan will put those doubts into your mind. I don't have any scripture references yet, but he tempted Jesus and Jesus was definately on his way to Heaven. I was saved seven years ago when I was six years old. Like you, there wasn't a drastic change or anything because I wasn't in to anything bad or whatever. I was just a little girl who heard the gospel and accepted it. Ever since then, I have had my doubts as to whether or not I am saved but I think back to that day and I can relive it so vividly it just had to be real. Plus, when I do something wrong, there is that still small voice saying, Don't do that, or No no no. That voice is the Holy Spirit in me. So, Good Luck in your Christian Walk and tell the devil to "Get thee behind me Satan"