8 days ago my baby boy got a blood test via vein inside his elbow and
a urine sample via little bag on him. How long should these tests
take? They are "routine". I called the Dr.'s office and the
receptionist said that "if there was a problem then we would call
you". So if they don't call me then all is fine?

The results of such tests can be available within hours. It's quite
likely that the doctor has your son's test results on file, but if
they were unremarkable (meaning that they showed no evidence of any
abnormalities), there would be nothing notable to report.

Personally, I find it rude when doctors refuse to discuss test
results, but it is quite common these days. You can generally assume
that "no news is good news." If something unusual shows up in the
tests, you'll hear from the doctor. If not, you'll hear nothing.

Pinkfreud-ga is absoulutely correct; these results CAN be done within
a very short time. If the samples were collected at a doctor's office
however, there is about a 3 day delay in getting the results back. The
samples are usually picked up at the end of the buisness day, and run
that night. If any bacteria were seen in the urine, they may have set
up a urine culture and sensitivity test, which would add an additional
2 days to the turn-around-time. It takes another day to get results
back to the doctor's office, and then it often takes 2-3 days for the
doctor to review the results.

I would NEVER depend on the doctor's office to call you. I would never
trust the doctor's office to tell you if they don't call, assume all
is well. I have seen countless cases where abnormal, and even fatal
results were filed without the doctor ever reviewing or knowing about
them.

Ask your doctor's office to send you a copy of the actual results.

I did not mean to imply that you should "trust the doctor's office to
tell you if they don't call, assume all is well." However, this is
what many doctors' offices will tell you. Whether to trust them or not
is entirely up to you. If your doctor gives you the brush-off when you
ask sensible questions, it may be time to go looking for a new doctor.