Should I goto the doctor about my cut on my knee?

So my boss told me my cut looks really bad and I should go to the doctor she gave me 2 days off work for that. How my cut looks: Red and swollen around the actual cut then kinda pinky red going in then in the middle a black kinda colour, to me it looks like its scabbing. How it happened: I was on my bike and forgot to turn and hit it of the kerb at about 15mph give or take then kinda hit in to a wooden wall Pain level: It's painful and fells like I need to stretch it but when I do it takes a bit of time cause its 3 days old so it's new but when I do stretch it I can do it all the way it locks. I washed it and cleaned out the gravel then had a shower then the next day had a bath and today I but baby oil on it. Do you think I should go to the doctor?