Chow in Heat - is bleeding during diestrus normal?

[GoHokiesGo]

This is my first dog I've had that wasn't already spayed once we got her. Honey is a retired breeding dog (she's 4.5 yrs old), so she's had 2 litters in the past with the most recent being this past spring. After buying her from the breeder, we decided to wait on spaying her by a bit because we would like to show her and see how she does in dog shows. We've been told that she'd do well at shows, so we're hoping to give it a try for a year or two to see how it goes.

She's currently (I believe) at the last part of her heat cycle. Based on my reading, dogs have 3 parts to their heat cycle: Proestrus, estrus, and then diestrus/metestrus. I'm going to describe the colors, so don't read if it disturbs you! She started at the beginning of september with very light bleeding, I guess you'd call it spotting, and this lasted just a tad over a week. Then she started with a slightly orange/brown discharge, which I read is the middle stage of the heat cycle. We were with her at all times during her heat and keep her indoors when not directly on walks, and she only interacted with my parents neutered aussie when we visited them during that time. This lasted maybe 2 weeks, and then she basically seemed normal.

Fast forward to this week (so roughly 4 weeks total), and she started bleeding again last thursday. Most of the things I've read online have said that generally the heat basically just goes away, but there are a few places that mention secondary bleeding at the end of the heat cycle. The bleeding is definitely heavier this time, and I had to get a set of the doggy diapers/pants for her as it was leaving marks all over our carpets. I took her to the Vet on friday for a heartworm bloodwork check, and I asked them about it then. The Vet said that it is not uncommon for some dogs to have abnormal heats, and to keep an eye on her over the next few days. If it continued for much longer, they said to bring her back in. The color has turned a bit lighter red now, and it's slowing a little bit.

She's been a little withdrawn from us, but not a huge change in behavior. When I first put the diaper on her, she'll go sit in her cage for about 10 minutes before coming back into the family room with us like normal. Other than that, her behavior hasn't seemed too out of the ordinary.

I was mostly concerned as I've never dealt with a dog in heat before, so I only know what I've read on the internet. I know some of you have Chows that aren't spayed, so are your experiences similar? Have you heard of bleeding on the last stage of their heat and how long did it last? I'll be returning to the Vet again in another few days if it doesn't continue to slow, but I figured I would ask on here while waiting to see if anything similar happened.

Thanks!