What's wrong with my knee?

So Last Summer, I was racing dirtbikes and the front tire blew out on me, when I wrecked the Bike fell on top of my leg, and my knee cap hit a rock. I was rushed to the emergency room and it was about the size of two softballs within 3 hours, and turning black and blue. They thought I might have cracked my knee cap but it was soo swollen they couldn't see past the tissues in the x-ray so they told me to come back in 3 days. I never went back to the doctor, because we were going out of town on vacation, and I didn't want to miss it. Well I was on crutches for 2 months, and my knee was black and blue, with blood settled at the top of the skin, and swollen for months. It's been a little over a year, since the wreck, but when I get cold I notice my knee swells a bit, starts getting blue, and a little pain in it, like sore pain almost. If I do alot of running or standing up for long periods of time My knee gets sharp pains in it all the way up to my upper thigh. Do you think it is from the accident? Maybe it was cracked, and it healed the wrong way? Think it is serious enough to go to the doctor, or just take advil when it starts hurting and deal with it?

Serious answers Only please. Thanks in advance. :)

i had a bike crash very similar to yours, bike landed on me knee, n theres a little bag of fluid behind your kneecap that i popped when i crashed... n it was internally bleeding... did exact same as yours n swelled up really bad..
but its best to go to the doctors as they're may still be a big problem with it

Welcome to the world of motorcycles. Go get it xrayed. I have broken both of my legs and I get aches and pains all of the time. it is the price you pay if you want to play. You need a doctor not yahoo answers.

You from England if so why don't you go get a MRI or cat scan with contrast don't mess around i pay through the nose because i don't have socialized medicine what's your excuse?

visit your doctor for completely treatment, pain killer like tramadol...used just a moment

I think you should go to the doctor, why deal with the pain when you don't have to?

you should have gone to the doctor long ago you need an xray, sounds like you have some damage there.

go to the doctor streight away this sounds serious

It sounds serious to me. I have been a long time knee injury sufferer. I tore my ACL from swing dancing and it's never been the same. The swelling is a warning sign that something isn't right. If your knee never healed the way it was suppose to, the swelling can persist or months or even years after the incident. Do you have full flexibility? I would go to the Doctor and ask him for a MRI and X-ray. Make sure they check out your ligaments in your knee, because i had the same pain when i tore my acl in half.

Good Luck!