Piercing question!

💙C

I’ve had this cartilage piercing since September and tonight all of a sudden it’s swollen, red, and kinda painful. There’s nothing really coming out of it except maybe some clear stuff. Anyway, it’s been fine so why all of a sudden is the whole upper half of my ear swollen? I took a picture of my other ear for comparison. Sorry if the pictures suck but they’re kinda hard to take close up haha.