Contact on Text (iMessage)

So I have an iPhone 7 Plus but before I upgraded from 6 Plus I was already having this problem. I have one contact that when I text from my cell phone that it has the last thing I left in the texting screen. If I've left a . a letter a emoji anything and leave it there for a minute or so it'll remember that last thing I've typed even a full sentence. I have gone as far and deleting my contact gone through the address books and making sure it wasn't anywhere else. Deleted that full message and started over and it's there. It is only there with that one contact. I have no issue with no other contact but that one. It's like a macro. Not sure how to fix it and it's just annoying. Help Please...