None of us can answer that for you. The only way to truly find out is to go to your doctor and have him run the Hepc tests. You can get Hepc via piercing and tatoos. Most are careful but there are some that are not.
Your question-"Am I at risk?" has a simple answer--yes.
Piercing, as a hepatits c transmission vector carries low risk, but it exists. Even if the instruments were not sterile, it would require that they were used on someone with hepatitis c before you. This drastically reduces the chances of infection, as appx 2% of Americans are infected.
Explain your fears to a doc, and they will run a simple antibody assay (they draw your blood) to determine if you have ever been infected.
To sum up: Yes, the possibility of transmission of the virus exists through piercing, but the probablility is not very high.
Yours in truth,
Mr Liver