Hi there.
Please go across to a 
dermatologist or gynecologist & get this material examined under a microscope. 
It does not appear a 
pregnancy as 'eggs' will not look the way you describe.
As for an 
STD, is there any particular reason you may suspect one? If so, yes there is a chance. Is there any itching, pain, burning etc associated?
If you say same partner 9 mths, this too unlikely. It is probably just a result of a 'missed abortion'. One way to find out is to do a B-
HcG test that will give you a titre & if the titre is falling, this will help clinch a diagnosis.
Good Luck & wish you all the best  in the treatment. Do a gram stain of the discharge & then your doctor can decide how best to treat you. Cheers!
Dr Praveen Rodrigues MD
Dermatologist & Venereologist
Vikram Hospital, Bangalore, India