Sudden gum pain and bleeding

Within the last week, I've gotten some very *sudden* gum bleeding and pain. By sudden, I mean that last week, brushing and flossing did not hurt my gums at all. Last week, my gums did not bleed even when flossing. Now, my gums are bleeding where the tooth meets the gum under about 4 teeth just by normal brushing. Also, the inside of my lip  also is very tender.

Initially, I thought it may be just the starting stages of gingivitis or something, but the suddenness as well as the fact that I didn't have bleeding before while flossing make me think it might be something else. I don't recall eating anything hard that could cut my mouth, but I did happen to get very sick (which I thought was food poisoning) for about 2 days right before I noticed the bleeding. This is the first time this has happened to me as well. Any ideas on what this could be?

[scottma]

Seeing a periodontist is advised.

[Jay32]

Any idea what this may be? I would think that gum bleeding from normal brushing would not suddenly occur when literally a few days ago, the action of flossing produced produced no blood at all, or that parts of my lip are sore.