If you are sharing needles with someone who has hep c you should be tested for hep c antibodies.
If you test positive for hep c antibodies a second follow up test that looks for the actual virus in your blood called the HCV RNA by PCR test should be done to see if you are currently infected with the hepatitis c virus.
Sharing needles is a risk, period
From the CDC FAQ for the general public about hepatitis C
“People can become infected with the hepatitis C virus during such activities as:
Sharing needles, syringes, or other equipment to prepare or inject drugs
Needlestick injuries in health care settings
Being born to a mother who has hepatitis C
Less commonly, a person can also get hepatitis C virus through
Sharing personal care items that may have come in contact with another person’s blood, such as razors or toothbrushes
Having sexual contact with a person infected with the hepatitis C virus
Getting a tattoo or body piercing in an unregulated setting”
Found this by googling does hep c virus exist in body fluids from an article in medical news today
“In almost all cases, hepatitis C is spread through contact with infected blood. Dried blood deposits may still carry the virus. Other bodily fluids, such as urine, sweat, or semen, do not carry a high enough level of the virus to pass on an infection”