The thing about utilization rates is that it all depends on the bank you use and how frequently they share that information with the credit bureaus. For instance, my Discover card balance seems to be updated almost weekly with TransUnion.
Utilization rates for the purpose of your credit report have nothing to do with you card's billing cycle. In other words, you could be in the middle of a billing cycle and have your utilization rate updated with the credit bureaus. My Capital One card's utilization rate is updated fairly frequently. The billing cycle is for purposes of charging you interest on your charges, and has nothing to do with how or when the card companies report information to the bureaus.
Your credit score is going to gyrate up and down on an almost-constant basis regardless of what you do, because there are countless pieces of information being received and analyzed all the time. The precise scoring models are a closely-held secret, so nobody can tell you with any accuracy how any one item may or may not weigh on your score.
It's more important to be concerned with the bigger picture of what your score looks like over a period of time, say several months, rather than worry about it on a week-to-week basis, unless there's a sudden sizable change, which could be an indication of activity you need to be looking into. It's probably a good idea to use one of the free credit monitoring services to track your score. Some of them update only once a month, while others either update on a regular schedule if there's no new activity or they'll update when an event (such as an inquiry or account update) occurs. Understand how they update their data before signing up with them.
The free credit monitoring services are not all created equal, either. I use three just for the sake of it, and I noticed that one of them lags pretty badly in reporting information I already get from the other two.
A good rule of thumb (according to several major credit sites) is to keep your card utilization rates below about 25% (some say 30%, others say 20%, so I split the difference), because it shows you can manage credit.
The danger of a high utilization rate and why it affects your credit score is that if you're carrying high balances, they can interpret that as a sign you are living beyond your means and are using credit cards to make up the gap between income and expenses. There are other ways they can see this, but that's the big one.
I hope this helps.