Hi.
You have not mentioned how you sustained the bump on the head.If it was insignificant then you may not have cause for concern because not every bump in the head results in serious injury.
But if you have had a fall or been in some kind of an accident then you do heve reason to worry.
Occasionally, a blow to the head may be severe enough to cause bleeding in or around the brain. This type of bleeding is serious because it can put pressure on the brain.
So i suggest you go visit your doctor immediately especially if your head ache is associated with vomiting or any other unusual symptom.
You would probably require a CT scan to rule out any danger.
Could it be something of a spider bite or a bite from a tick? Only reason I ask is because sometimes some symptoms can come from the site of an insect bite especially with what season it is now. Have someone (maybe a general doctor) have a look at it. If it doesn't appear to be a bite, again, have a doctor check it out. Could be as simple as a little cyst that pops up until your body absorbs it again.
I would doubt that they are related, but to be on the safe side, I would have it checked out.