I have recently discovered a blister on my lower right leg. It appeared literally overnight, two days ago. I discovered it after a night out and am told it looks like a brun mark even though I'm pretty sure it isn't. It was very swollen doesn't really itch but its with a red outline. At first I burst it with a pin I did starilize it and drained the fluid, I woke up today and it was filled fluid filled again so I drained it lightly because if I put presher on it it does hurt. So I just put a big bandaid on it so it isn't in contact with my pants. I am not sure what this blister is, what caused it or what to do with it. Please help!

It could be anything from a burn to a bug bite (spider maybe, and not necessarily poisonous, or you would have known by now) to an ingrown hair to someone putting ice and salt on you when you weren't looking.
Never ever poke a blister without a thorough washing with soap and water afterwards, and an antiseptic cream under the bandaid, with frequent washings after.
One little regular bacteria gets in a break in the skin, and you can end up with a raging rash infection that spreads like wildfire and you end up in the hospital.

Answer back in a day or two...