when i use my needles i dont dispose it until i am done with everything so i keep the open ones with the closed ones in my safe. but recently i opened all of them to check them out, and today i used a needle to inject myself, adn then it dawned on me that iw asnt sure which needle was the used one and which one was new. i used the one on monday and put it right back in my safe. do you think im running into risks???