Scared of my parents finding out I smoke weed?

I have been smoking weed for the last year now. I'm not a heavy smoker, maybe once every two months, but that doesn't make it any more legal. Or me any less paranoid. The only times I smoke would be when my parents are out of town for a few days or something. The only people who know I smoke are my two older brothers, but they've long since moved out. My folks are gone to visit a friend in another city and won't be back until tomorrow, they've been gone since Thursday.

So. I went outside on our patio for a smoke this afternoon and another after dinner this evening. I took the clothes I was wearing while I smoked and put them in the washer, and disposed of my joint by putting it out and throwing it over the fence of our yard. This next bit is exactly why I'm going to quit smoking as of now.

I know they're coming home tomorrow, so I'm pretty paranoid. I'm afraid the smell won't come off my clothes. I'm afraid maybe the smell of the smoke got into the house. Then I'm afraid it'll still linger outside the door. I've never been caught yet, but I think they may suspect it.

Am I being too paranoid?