Why does my MacBook Pro keyboard autocorrect the word "I" to something else?

Hi everyone,

I have a 13 inch 2012 model MacBook Pro with the 10.12.6 macOS Sierra software update and it hasn't caused me any problems until today. For some reason when I use the word "I" in my messages app on my MacBook it somehow autocorrects itself to "A" with an emoji of some sort. I'll attach a picture below so you all can see what I'm talking about.

The "A" seems to be replacing "I" in some of my messaging threads but others are just fine. I have looked at my shortcuts on my keyboard and there's nothing there that would have "I" being replaced. I reset my keyboard settings on my iPhone since all its properties are synced (I think) to my MacBook but I don't know if that actually helps.

Has this happened to anyone before/can anyone help me? It's such a nuisance 😕😠