Can you get a STD with in 48 hours I just want to know if I have a std

Wait 'til 4-5 days. 48 hr is too soon for symptoms. Rarely symptoms of gonorrhea or herpes may start that soon, but most STDs require a few days, or up to a few weeks, for onset of symptoms. Testing for gonorrhea and chlamydia is best delayed until 4-5 days after exposure; chlamydia testing takes a few days to be valid. Syphilis and HIV blood tests aren't valid until 6 weeks after exposure. Partner also needs testing.
Yes, . Yes, it is possible to have symptoms from a sexually transmitted disease shortly after initial contact. The best thing is to get checked out by your physician. Please remember safe sex practices in the future. Not all std's are easy to treat. Don't forget about aids... Best wishes.