At one point in taking those pics, I'd changed the aperture to see if I could get a clearer shot. I did, all right... I got a clearer shot of the dust specs! (That "specs" is Blogger's spelling, not mine... please see comments below!) See?
Yep, those are very magnified tiny dust motes or fibers on the sensor inside my camera. Not a good thing for getting decent photos. I was hesitant to go inside my camera to clean it... just plain scared to do it, actually. But I searched YouTube for videos on how to clean a DSLR. There are plenty there, and I watched a number of them. Some of them tell you to actually get in there and touch that sensor with a special tool and cleaning fluid. I didn't have those particular tools, but luckily I was able to just blow off those specks with my air blower tool from my cleaning kit.
I won't point you to any particular DSLR cleaning video, because there are many helpful ones, except I do want to mention this short one, because it showed how to see if your sensor is really clean. I had to go through the blowing and testing a couple of times before I got a completely clean screen, but I did it! Here's my test result:
Squeaky clean, huh? :) The job really wasn't as scary as I thought it was gonna be, and I wouldn't hesitate to get in there and do it again if it were necessary, which I'm sure it will be eventually. Every time I switch a lens, there's the potential of getting dust in there. I feel like such a pro now - ha!