I Have A Lump Where A Tooth Has Decayed, The

I have a lump where a tooth has decayed, the tooth is gone. However, I just noticed this lump about a month ago, and the tooth has been gone for much longer than this. It is not painful, and is a decent size. I have no problem feeling it with my tongue. It should also be noted that I was waking up with some blood in my mouth a couple of weeks back but that has stopped. Another on going pain that I have is I feel soreness in my sternum, kind of like a straining pain, that has not gone away just yet. See links to pictures to see what I'm referring to:

http://tinypic.com/r/alpye9/9
http://tinypic.com/r/w1pdvr/9

Thank you in advance for your help, I'm very worried this could be something pretty serious.