My bil had a vascetomy and the dr did tell him in rare cases a 3rd tube is present and can open up later.
Ya they didnt know, He never went in to folow up so the doc to see his sperm count, Just a year later she was pregnan and then he went in ( confused of course) and the doc said he has a third tube, He said it was rare and you dont know about it unless he had gone to the appt, he skipped on. I was just woundering ifany other guys have heard of that. Its kinda interesting. :)
Did the doctors tell him he had 3 tubes? Hell I don't even know how many a man is supposed to have, I am female, but what I dont understand is if the doctors were in there and they cut 2 of the 3, why not just cut the 3rd too, to be on the safe side? Are you absolutely sure that your bf has had a vasectomy done and has not just told you that because he doesnt like to wear rubbers?
However I do know that a woman can have her tubes cut, burnt and tied and she can still become pregnant. Its rare, but it does happen. So maybe if he did infact have a vasectomy something happened and he is one of the rare cases that slipped through the cracks and it wasnt a 100% successful surgery.
Sorry I couldnt give you more of a concrete answer, but sometimes surgeries have flaws, and maybe in this incident it was an oops. I hope you find the answer you are looking for though. Good luck.
Aurora