Question about oxy!

Okay so this friday i planned on trying oxy for the first time. I wanted to play it cautious so i started with 10mg. I felt no effects so an hour later i took 5mg more. After 20 more mins i took 5mg more adding up to 20mg. I felt no effects and that was it. Some people suggested taking the 20mg does all at once and after smoking some weed for me to feel the effects. I told myself i wouldnt do it again until next weekend because i dont want to make a habit of it. Well its sunday and i am thinking about trying it again since i already smoked some weed. Im just curious of how it will feel and i think i wont do it again once i figure out how it feels but im scared its the drug thats making me want to do it again. The problem is im probably busy next weekend so i wont be able to try them for 2 weeks. Today is a good opportunity but im scared its too soon.