Sweetie, there is no safe zone. You risk pregnancy any time you have unprotected sex and the withdrawal method isn't a method to prevent pregnancy. So, you risked pregnancy ESPECIALLY if you are irregular. All you can do is take a test if your period is late. And great news about weaning off the pain killers. We have a great addiction forum that I don't know if it is an addiction for you at this point but either way, they are great at talking about withdrawal and we also have a pain management forum where people discuss these things and get help. Hope it all goes well! good luck