Fishy smelling watery discharge from vagina is an indication of bacterial infection, You need to get treated with antibiotics consult your gync for further advise.
vaginal gel and Susten
injection contains progesterone
which is used to maintain pregnancy
Crinone is a vaginal progesterone, so absorption is from vagina. and Susten injection absorption will be from the site of injection.
But both have same mechanism of action, and both are given for same indications.