Re: mole appearing overnight?!
Did I understand you when you said it looked like an "Irregular" shaped freckle? Any mole that is an irregular shape should be looked at. The fact that it actually hurts too makes it something to have looked at.
As far at it popping up overnight, I just had one do that about a month ago on my arm as well. I went and had it checked out and it is fine. But, mine wasn't at all painful and is round. No irregularities in the shape. And it didn't hurt.
I don't want to scare you and I wish that I could provide some peace of mind but, in my experience...and I am a very moley person as I was born and raised in the 70's before anyone was really concerned about the effects of the sun on ones skin...moles don't hurt. Not when they first appear and never after. That is what really concerns me. The fact that it just popped up is nothing that concerning. They have to appear sometime.
How dark is your new mole? The really dark ones are usually kind of suspect too but, this new one may not have all its color yet.
Please go get it checked out. If you can, make an appointment for today. Tell the person who answers the phone what you posted on this board...that it popped up suddenly and hurts a little. If you express such a thing, they are better about getting you in sooner than later as some offices can be pretty packed as far as their schedule goes. Better safe than sorry and, the sooner, the better!
I am so sorry to sound so urgent! I really don't mean to scare you.
Take care and keep in touch