S.S.
Don't worry - my baby hated tummy time, and didn't roll over until after 6 months. My doctor said it was nothing to be concerned about - some babies don't do it until after 7 months. But try to give at least 5 minutes of tummy time a day - you can try to make it fun for your baby by giving him mirrors and fun textures to play with. But really - don't sweat it. My Baby hit all her other milestones like crawling and walking right on time. All babies develop at their own pace.