TMI!!! Old blood odor?

ladies! last day of AF was sunday. i was feeling really wet and tried to feel it with my fingers it was kind of creamy white but a lil bit yellow. i smelled it and it had a really strong odor.... like old blood, but also like a fishy odor.

i have washed my hands like 3 times and the odor still there.

i was testes for STD's like 2 months ago.

Any idea what could be causing this?