Older Siblings and Pregnancy

My son will be 7 next month and recently has been waking up in the middle of the night. He comes in my room around 2 am in tears and requests that I lay with him on the couch and snuggle. I think although he's excited about the baby, he may be having mixed feelings about sharing his mommy. I feel terrible because I was a single mother up until 2 years ago and although he's adjusted very well to having 2 brothers his age, I think having to share his mom is an entirely different feeling and he's not handling it well. Am I being paranoid?