NO STDs give symptoms in just one day. Some of them never give them at all. But you had unprotected sex so you should test as follows :
-3 weeks after the exposure, for chlamydia, gonorrhea.
-6 weeks after the exposure for syphilis.
-3 months after the exposure for herpes.
Regarding HIV, if you go for a duo/combo ag/ab test, it will be accurate 28 days after the exposure. If you go for a normal antibodies test, it will be accurate 3 months after the exposure.
You should get tested, discharge could be a symptom of a std, but it’s usually present with urination and discomfort. You had an exposure with someone your not sure of their std status.