It's Bad.... real bad!!

Last Sunday Joe was helping Joseph ride his bike. And since Joseph isn't quite confident enough yet, Joe had to run right next to him, ready to grab on at any moment. Well that moment happened and Joseph wobbled on the bike and fell over...but luckily for him Joe was there to grab him before he hit the ground and all was well, right?? WRONG-- while Joe was grabbing him, the bike fell onto Joe's leg and cut/bruised his lower leg/upper ankle. No big deal, we thought...for a couple days it was kind of tender and bruised, but the wound seemed to scab up and heal (i thought). I just figured it was a regular bruise type boo-boo that would take a few days to go away. BUT....a couple of days ago, it started swelling up and yesterday we noticed that not only was it doubled in size, but he had a black and blue line across the side of his foot. And today, the whole foot is becoming black and blue and is even more swollen.....

I have to admit that I am pretty worried about it. I have finally scared him into going to the doctor (telling him that it is probably severely infected and that could move up into his leg and make him very sick...right?) tomorrow, so we will see what he says.........

Any ideas? Anybody ever seen (or had yourself) anything like this???

***UPDATE****

All is well with Joe's foot.... per the doctor, this is the normal healing process; it is not infected, sprained, fractured...whatever!! The reason it is so bruised/black & blue is that all the old blood from the original injury has ended up there (thanks to gravity)!! Ohhh, I feel so much better now that I know he doesn't have some raging infection. And yes, I am a worrier..BIG time!! (i don't know how I ended up being such a worrier--- both my parents had such easy going, laid back attitudes with me growing up...)