Recently I recieved junk e-mail, and the sender is listed as my own e-mail address! What's going on?

I have now received three spam e-mail messages to my yahoo account and the sender is listed as my own e-mail address. After the first one, I changed my password, but it doesn't look like they have actually been sent from my account, only that they appear to be sent from my account. They each have spam messages and attachments. What is going on, and how can I determine where the e-mails are actually coming from?

Recently I recieved junk e-mail, and the sender is listed as my own e-mail address! What's going on?
It is highly unlikely that anyone else has taken control of your account. It is actually a simple programming trick to make an email LOOK like it came from someone else's account, in this case YOUR own account. It is just the latest trick to get you to open the spam mail. DON'T. Just delete it.
Reply:Its just a hacker. Delete it.
Reply:If you open them it could be a virus. If I was you I would leave them sit unopened for awhile till you can figure it out. Then just delete them. Don't mark them a spam cause it might hurt your real account. It will pass someone phishing
Reply:hack. better to delete it. i would delete it, i almost got the same thing once also, thankfully someone told me the same thing so i deleted it