Hi there, although I have not experienced this I have been through a thing called craniostenosis and have just finished a major head reconstrution for my now 2 year old.
We did meet alot of parents with the same thing as you though.
It sounds like you have a good Dr as long as he continues monitoring this.
the CT is imperative and they need to look at doing these thing soon. If it is fluis between the scull and the skill this can be fixed with a basic drain and if it is within the brain sack they will do something called a shunt ( similar to the drain but into the scull) the thing is all of this maybe very premiture, but I would incurrage you to research on the Net come up with as much info as possible so 1 you know what to expect and 2 if you are not happy with your dr you know when to get another opinion.
I do hope I havn't scared you I did find that knowing everything made it a lot less difficlt when we had to go through anything.
Hope I have helped and I will be thinking of you!

Turns out it is a small skull fracture and the fluid is blood. The swelling has gone down and he is doing very well. They say it should heal on its own. We are following up with a neurologist to make sure everything is okay. We will also be doing more xrays and another CT Scan to follow up. Thanks for your reply.