Hair follicle drug test...should i be worried?

SO, here's the story. I smoked pot like 4-5 times in my 19 years of age. Not a lot of weed, everytime i did, i was with my friends 3-4 people and all shared a cigar rolled blunt (swisher) and all smoked that. so at most, i probably got like 5 hits. this was like 3 3.5 years ago. just recently, i think not even a month ago me and my friends did pot out of a bong. i had like 3 hits total and 2 good ones and i was feeling "good" so i stopped and let the others finish. just a few days ago, i got a job offer and they want a hair follicle drug test done and i'm worried about it because i took 3 hits like 3 4 weeks ago. I'm a heavy person (260lbs) and rarely exercise but drink lot's of water. Oh yea i forgot to mention, in 19 years i have never cut my hair. NOW, should i be worried about the drug test? I have never done anything else besides marijuana and beer. i'm just worried about it so i wanted to post on here and find out if anyone can help me out, that would be great. thanks:))