Photo Gallery

Hey all..I know this might be a simple fix but this issue has been bugging me..Let’s say I have a article with the photo on top of the article, and I have 3 photos for the gallery at the bottom of the article, now when I upload the 3 photos and click insert gallery the photo at the top of the article inserts it self in the 3 which makes my gallery 4 how can I stop the main photo from joining the gallery? I hope I explained it clearly I did my best thank you…….