Dude, it takes 28 days to get clean naturally from THC. 7 weeks is plenty of time to detox. So, have a coke and a smile - and go take the test. People who say they failed after 60 days must have some extra-ordinary circumstances surrounding their situation. Drinking some water before the test is fine, just don't over do it (you don't want the test to come back diluted and fail.) Stop worrying.