A week or so back I noticed the joint above my knuckle on my left index started to ache a little bit. It only hurts if I curl my finger up or fret any notes with it. Its a very slight pain, I could easily play through it but I was wondering is this just from pressing too hard? Ive only been playing for 3 months and I remember it started when I practiced way too long two days in a row (6~ hours lol). I was doing a lot of open chord work so that might have something to do with it.

What should I do to get rid of it? Stop practicing for now/ice/icy hot?
It's probably from a sudden jump in practice and from fretting too hard, yeah. Just take a break for a couple of days and then take it easy for a while after that. If it hurts, stay on a break until it doesn't.