Immediate Bruising On Thigh Post Accident, Growing In Size, Discoloration Followed By Lump, Discomfort On Applying Pressure. Help?

I was recently in a bicycle accident where I flipped over the front of my handlebars at about 15-20mph. When flipping over the handlebar, my inner upper left thigh ran into my bicycle stem/handlebars. This caused an immediate bruise , which continued to become larger and turns a variety of colors in the passing days. Now, the bruise has begun to fade; however, a round-like ring shaped lump has appeared in that area. There is slight bruising in that area, some discomfort when pressure is applied to it, and is seems to be slowly enlarging in size. What might this be? Also, should I make an appointment with a doctor? Thank you in advance for your help.