Initial Time Machine backup.

I recently purchased a 1TB Seagate external HD to use with Time Machine on my mid-2011 iMac. I have never used TM previously, but I read and watched some tutorials to the point where I knew what to do.

The HD was recognized, I initiated TM, and we were off. I would say the average speed was around 1-2GB/per minute with the estimated time to finish around 3 hours. No problems at all.

However... there's now a holdup. It's been over 16+ hours and I've hovered around 28-29GB for probably 15 of these. Is this normal for the first backup or have I stumbled across something? I can't wrap my head around the first 28GB taking less than an hour and the next GB taking upwards of 15.

For what it's worth, I selected to encrypt the drive and crated a password.

Any help is greatly appreciated.

Here's a picture of what I see.