Can you get STD results the SAME day??

I recently found out I got chlamydia and the only person that could of gave it to me is my bf but he just told me he got checked today and got his results back TODAY and everything came back negative?? That doesn't make any sense. He also told me that if you had chlamydia before you can't get it again? Nothing he is saying is making any got damn sense and I believe he's lieing . What do you ladies think??