Not day one, no. You may need to up your sub dose a bit to feel "ok", but I would prob just continue onand pretend it didn't happen, medication-wise I mean. You are definitely doing the right thing by using such a low dose. Docs almost always prescribe way too high a dose... just ridiculous.
If you don't mind me asking: are you planning on tapering or doing more of a maintenance with bupe? If trying to come off, I would make it as quick as possible. I was on only 2mg for a year (although prescribed 16mg lol) and still had a hell of a time coming off of it. Of course considering the cravings and usage you mentioned, it may be best to go for maintenance. I generally don't consider bupe a very good maintenance drug because it didn't do much for my cravings (even when I used the prescribed 16mg at first), but if you're able to stay at the ultra low dosages you're using, that's a pretty decent position to be in. Just expect to still have some level of detox at the end
Best wishes
If you don't mind me asking: are you planning on tapering or doing more of a maintenance with bupe? If trying to come off, I would make it as quick as possible. I was on only 2mg for a year (although prescribed 16mg lol) and still had a hell of a time coming off of it. Of course considering the cravings and usage you mentioned, it may be best to go for maintenance. I generally don't consider bupe a very good maintenance drug because it didn't do much for my cravings (even when I used the prescribed 16mg at first), but if you're able to stay at the ultra low dosages you're using, that's a pretty decent position to be in. Just expect to still have some level of detox at the end
Best wishes