It's just garbage the beer makes with fermenting. Fear not - you will see all sort of scary things going on that looks horrible.
you're good to go!! Looks great. It's just yeast and protean. Every beer is different. Some are nice and clean and some are NASTY!!!
My latest three 2.5 weeks old (secondary), 1.5 weeks and 3 days. notice the middle one got pretty feisty!