Ok so I periced my own cartilage with a safety pin a week and 2 days ago and the back of it is very red and swollen and it hurts pretty bad. Do you think it's infected? If so, how do I get the redness and swolleness to go away? PLEASE HELP! Thanks.

Of course it's infected. The pin was laden with bacteria which you introduced into your body, plus you made a hole for more bacteria to march right in. That's why you go to licensed piercers who use sterile needles and who give you instructions on keeping the area clean. Now you have to go to a doctor for antibiotics, and don't try taking someone else's, because there are different ones, and you have to take a full course. If you can find a day walk in clinic that is better than an ER in terms of wait and cost.

Please do go. I didn't know I had a hole behind one knee from a bug bite and bacteria moved in, eventually working all over my entire leg (cellulitis) and even oral antibiotics didn't stop the spreading. Your skin is your defense against bacteria!