Will I be tested again? Temp to hire

Hey everybody,

So I recently passed a drug test after staying clean for ~40 days (I was testing clean after 3 weeks, but the test wasn't until that 40 day mark). I was hired by a huge investment banking company as a financial analyst, but I was hired through a staffing agency, and took the drug test through this staffing agency as well. So, technically, I currently have about a 3 month contract, but I've heard that almost all contractors do get hired full time once their contract ends.

So my questions are: Can I expect to be drug-tested again once my contract ends and I'm (hopefully) hired full-time? Would the investment banking company then conduct their own drug test? And should I be worried about any random testing in the meantime?

If anyone has any experience with this type of situation and can offer me some input, it would be much appreciated. Thanks, guys, and good luck with your own drug testing issues...