How To Cure Head And Back Pain After Having An Injury?

I had a bicycle accident 3 days ago, I fell off on my bike and hit the back of my head on the pavement, the part was swollen and now it's purple, I haven't experience any symptoms of internal bleeding like, vomiting, nausea, or dizziness, but my head is painful and I am thinking that it maybe because of this or maybe because I have my monthly period, anyway, how long time will until an internal bleeding manifests? do you think i need to go to doctor?