Question about being in DEP for U.S Navy?

I was looking at my paper work from meps the other day and I totally screwed up about drug use. I'm 19 years old and I smoke pot twice when i was 16..and thats it i never liked the feeling i got from it and i messed up on the question cause someone told me they only want you to answer yes if you have smoked it in the past year or 2. So what should I do I need a Secret security clearance for my job and I dont want to lie about it, shoudl I tell my recruiter, or will i be in trouble and get kicked out of DEP for it? I ship in august.