Nothing in your picture suggests infection; you'll be fairly certain when you have an infection. What you are seeing is a normal occurrence when dry-hopping. A combination of the hop resins and CO2 in suspension can make for some weird looking beer when sitting in secondary.
Oh - and 'several weeks' is far too long to dry-hop. 7-10 days is nearly perfect, IMHO. You risk some grassy, raw vegetal flavors.
This is a (purposeful) lactobacillus infection for comparison: