Will common blood tests at a hospital detect HIV?

I recently had a blood test done at a hospital.  They took three separate samples and were looking for drug use (wasnt on drugs however they suspected use).  Thats really all I know about the tests.  Before then I had reason to think that I might(big might) have been exposed to hiv.   A friend told me that when conducting blood tests hospitals always screen for stds.  Anyone know if this is true?  

[Brian123]

No. they do not.
You would have to sign consent forms to be tested for HIV and an array of STD's.