NY employment law, can employer conduct random drug testing

Radom Drug Testing.: On Monday Nov. 08 I took a drug test and was cocaine positive Im waiting for test B.I have never took drugs in my life.I have been send home today by my supervisor.My life feels like hell right now.I feel like I dont deserve this.I dont know how cocaine even got to my system in the first place,Ive worked for the company for 5 years.I went through several random tests before and was always clean.I wasnt afraid to take the test when was presented with random test papers.Can I fight this in court?Can cocaine get to your body by having sex with somebody 1 day prior testing?I also want to say that I didnt take any medications lately.Im healthy 35 y. old woman.I think that the whole think is unjust.Im really hurt by this.They should look for other people DNA or oral fluids.Please help. - Is this your question? Add additional information