Two days would be really early to see symptoms, though not impossible.
It's definitely too early to test, though. You should wait until 5 days has passed. In the meantime, make sure you are drinking plenty of water - dehydration can cause some mild irritation with urination. Lay off alcohol and caffeine, which can irritate the bladder and are dehydrating.
Any time you have unprotected sex, you are at risk for an STD. Did you have unprotected vaginal or anal, or oral sex?
You can test for gonorrhea, chlamydia and NGU at 5 days. This will most likely be peeing in a cup. Don't urinate for at least an hour before testing.
You can test for syphilis at 6 weeks. If you get a sore, go to the doctor as soon as you see one.
You can test for herpes with a type specific IgG blood test now, and if it's negative, test again at 4 months. If it's positive now, it's a pre-existing infection. If it's positive for type 1, it's probably an oral hsv1 infection (think cold sores or fever blisters).
You can test for HIV with a 4th generation DUO test at 28 days. If it's a 3rd gen antibody test, it's accurate at 3 months.
There is no test for HPV for men, and it could take months to show symptoms, if you do ever get symptoms. Most people don't, and most people will get HPV at least once in their lifetime.
If you get any sores at any time, get to the doctor within 24-48 hours of them appearing. If the doctor thinks it's herpes, insist that they do a type specific culture or PCR swab.