In my second pregnancy, they started to notice calcification of the placenta at around 32 weeks, I seem to remember. It was basically explained to me that that means the placenta is "aging", as I guess they all do, but mine was aging a little prematurely. I remember my doctor saying then he hoped we would get at least 3 or 4 more weeks (we got 5 and made it to 37!). I also remember a number of people (as I had frequent ultrasounds) asking if I was a smoker (which I am not -- and have never smoked a cigarette in my life), as apparently, they see these types of things far more frequently in smokers. I believe it is due to the high blood pressure (though incidentally, mine was higher than usual and kept creeping up, but never high enough to warrant medication). I was never told there was anything I could do to remedy it, and I'm sure if there was, I would have been told, as my doctor and nurses were very thorough. Nevertheless, it never hurts to ask your doctor -- perhaps there is something that may help in your case.
It sounds like it will be a few short weeks at most for you! How exciting! And you're right -- they will fly by! Best of luck and keep us updated!