I still get the jitters when flying season starts in the Spring for the first few flights. I get the jitters and my heart pounds hard when I maiden a new plane that I've put a lot of work and time into it.
And most of all, when I fly at a big events and about 1,000 people including "Big Shots from AMA" [:-]

are watching me fly. But other than that my knees don't shake and my jitters stop all in between flying season.
Here's a good one, LOL
I remember the day I first maidened a Warbird at my Club about 6 years ago. My knees started shaking, I could feel my heart thumping in my throat and my hands were all sweaty. It was so bad I asked the Vice who was standing next to me to take over for a few minutes until I got my composure back.

Today I just fly and so far when ever I get the jitters real bad, I say a silent prayer and ask that I don't faint!
So yea, it's normal, LOL you're OK!
Pete