Mirena IUD removal came out with blood-clot tissue

Hi,

My 28yo SO had a Mirena IUD inserted 4 months ago. After a couple months of feeling like she "always has a UTI", we decided to try removing it at home by pulling the strings.

She tried by herself for 30minutes but was unable to grasp the strings. One week later, we tried again with my help. It took about 10 minutes to find the strings and get a grip with two fingers and I was able to slowly ease it out. It was uncomfortable but not painful.

However, when it came out, there was a small, stringy blood-clot looking piece of tissue wrapped around the Mirena (see photo). We were immediately worried as this looks like it could be damaged human tissue. She subsequently expelled some fresh looking blood (see photo 2). Still no pain at this point.

She was able to sleep through the night with minor cramps and discomfort, no sharp pain, although we certainly were and are still concerned about this.

Questions:
1) What is this blood-clot looking tissue?
2) Does this look possibly normal / expected?
2) Do we need follow-up treatment?

Thank you so much in advance for helping us figure this out.