I Noticed On My Way Home From Work This Evening,

I noticed on my way home from work this evening, I felt tiny bubbles along the left side of my left middle finger, I tried popping them , clear liquid came out but it was painful. ive never had something like this before, it kind of feels like when I had a cold sore , I popped it , it was clear and it hurt , but it's on my finger. if you know what this is, please let me know so I know if its contagious or if I need to go to the doctor. I also don't know where I could have gotten this.