I changed the brake fluid a few weeks ago, and recently I noticed that the brake booster pump is running more than normal. Or maybe I'm just paranoid. Apparently the seal(s) can be damaged when bleeding the brakes if you push the pedal too far, which can cause it to not hold pressure as well.

It used to run once every other time I pressed the brakes, even if I pressed them firmly.

Now it runs every other time, unless I press them firmly (stopping fast, but not hard enough to activate ABS on dry pavement), then it comes on right away. If I'm holding the brakes for a while it sometimes comes on. When I start the engine it runs for a few seconds, then it waits a few seconds, then it runs for 1 more second. It does that even after sitting for less than an hour.

I did the power steering fluid before the brakes, and while I was doing that the pump never came on even though I had the key on the whole time to keep the steering unlocked. I haven't tested, but it seems like it would cycle on once or twice in the same amount of time now, based on how often it comes on while driving.

After a short drive yesterday, and some testing while I was parked, the motor was only slightly warm, so that's good.

Maybe you didn't bleed all of the air out when you changed the fluid.

I didn't let any air in, unless some got sucked in when the fluid was low.