Low does naltrexone

So I'm hoping I'm not gunna get abused for writing this, I'm a recovering drug addict and have had the naltrexone implant for years , it's a opiode blocker to keep me safe and stop any cravings that may happen , well I'm currently 10 weeks pregnant and my implant run out months ago , I was due to get a new one in May but found out I was pregnant and didn't get it done . Iv read up on getting it while pregnant and it's saying of the benifit outweighs the risk then go for it. In myself I feel fine like I'm not going to use again but for good reason I'm thinking I should still get it . Has anyone else been on naltrexone while pregnant ? It's used for more then drug dependence . Iv heard of low does naltrexone , just wanting to cover all basis before I commit to it again . Thanks ..