Should i get an attorney if a detective is calling me & questioning me about a crime I didnt commit?

My mom co-signed for a student loan for me 2 years ago. earlier this year I dropped out of school and defaulted on the loan. My mom said I better paid it or she will report me for fraud/forgery to get this off of her credit. I now have a detective calling me questioning me about it. Should I get an attorney even if I have nothing to hide? Doesnt an attorney cost a lot of money for something like this?