Well, as much as I want to discourage opiate abuse, opiates are natural substances, and although they are highly addictive, and can cause a baby to be born with a "habit", there seems to be no conclusive evidence that they cause probems with the reproductive system per se. Do get off the opiate before you decide to conceive. You've got to just "stop" and endure the few weeks of discomfort, muscle pain and irritability.
"Uncommon: Impotence, amenorrhoea, menorrhagia,metrorrhagia... "
I found it here:
http://docs.google.com/viewer?a=v&q=cache:Hv8J1im-lfcJ:www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/000697/WC500058505.pdf+buprenorphine+reproductive+system&hl=hr&gl=hr&pid=bl&srcid=ADGEEShy5-1OAEC_ci5pb9v8AT7eRKoADMKrHeMA0-A00A2LH2TkbS3UTNAXqaZCPBU08jFPZNDys9FcXpr8zlH9DGl1QjdEGIDTtGu81POGxh0k1-l3rofcdU4s0-46tmho2toMuQXY&sig=AHIEtbRxrI2FG9izn0kjTBuncBJeK8pKUQ&pli=1
I hope everything will be OK... And good luck...