I crashed on my mountain bike with my pelvis/groin taking the full impact on the end of my handlebars. I had a huge bruise/swelling that covered the whole front of my pelvis area (like wearing underwear, it was the whole area it covers in the front).

The bruising went away very quickly for a bruise but a rock-hard length-of-a-thumb-sized bit of swelling remains. All the other swelling has receded, so this little hot-dog of swelling is very prominent. It is just to the inside of the crease between my thigh and my pelvis. I am pretty concerned about it b/c it's been a week, and everything else has gone away except for this. I think my lymph nodes got overloaded and there's a traffic jam in there or something. Is there a way for me to flush them out? I haven't iced at all, and it kinda hurts to massage it.

The only other thing I can think of that it is is when your muscle takes a hard hit and ends up building calcium deposits at the point of impact. But that is for more repetitious injuries, right?