T slim blood in tubing

Hi everyone,
I’m a new diabetic/pumper, and today while in the airport I looked down to see blood in my tubing. I changed everything out (wasting insulin since I just changed everything out last night), but I’m wondering if anyone knows why this could have happened and if it has happened to anyone else?!? Thanks for the help!!

some discussions here about blood in the tubing:

https://forum.tudiabetes.org/topics/blood-around-infusion-site-is-this-normal
https://forum.tudiabetes.org/topics/blood-in-the-ringbase-of-the

and this one has some helpful tips from Capin101
https://forum.tudiabetes.org/topics/infusion-set-allergy