Should i worry about my swollen gum?

The past four days my gum around my back took has been very sore and swollen. i didn't feel any bumps and the tooth feels perfectly fine. It hurts when i touch it, use my cheek muscle(like when smiling too big or puckering my lips and moving it to the side), and when i touch my outside cheek. the second day of it hurting and being swollen i brushed it too hard and it started bleeding. i have been know to have a little bit of gingivitis but i am not sure if that has anything to do about it. but today it feels like a bumpish thing under my jaw that is sore when i touch underneath it, like a swollen gland or something. i just don't know if it is worth worryingabout and just go away. if so how can i help it feel better. i dont really want to have to go to th e dentist.