Hi. For Abut A Week Now Iv Have A Strange

Hi. For abut a week now iv have a strange feeling on the inside of my bottom lip just at one side. Inside it looks darker than the rest of my gums buts it's not a definate patch. The best way I can describe the feeling is like when you've been to the dentist and havng moved your mouth for a while then when you do your lip feels soft and a little swollen / sore without actually hurting. Almost like if you suck on a lollypop and your lips crinkle. I'm not sure if this is anything to worry about.? Any thoughts?