Creating a budget, but copy/paste throwing off by 1 (Edit)

I'm trying to make a personal budget, but for whatever reason when I copy and paste the pay periods, the cells get thrown off by one and I don't know why. Attached is an example. The highlighted area is the pasted part that gets thrown off. Any help would be greatly appreciated! or if you have a budget file that would be great too! Thanks in advance!

I'm re-doing this post as I never highlighted the issue in the original folder and I wasn't sure how to delete the attachment and reattach.. so sorry for the repost.