2nd time, fell off from the bike

On the way to my piano student's place yesterday, riding on a bicycle, suddenly the door of a car parking on street was opened in my way. Crushed into the car-door, I fell off from my bicycle and was thrown forward. Shocked and surprised. Since I landed on my shoulder, hands and back well, I have no cuts or abrasions on my body. Of course, I had a little pain in my hand and knee, but that's all. And fortunately there was no car or bus passing by me. I thought I was just lucky. The driver and his partner walked out from the car as soon as it happened and asked me if I was OK.
I feel pain in my knees and lower back today. Humm, I hope it gets well soon.