My little girl did the same from 7 days old (12-7) - we didn't sleep a wink and was advised by midwife to wake her every 4 hours as she had lost a bit too much birth weight.
She gained her weight again pretty quick after I increased her feeds (also ebf but never showed cues so I put her on a bit of a every x hours regime for a few weeks) and it was impossible to wake her! Stripped to nappy and sat up she would just snore away!
She has continued to do this and is now 18 months old, only disturbed nights we get are due to colds, coughs etc. She loves her sleep! I dream fed her at 11pm till about 7/8 months but then stopped as on a couple of nights I didn't she still went through.
Weight has maintained on her percentile pretty much since about 10 weeks consistently (apart from a blip around weaning and not crawling when we went up a bit too much!)
Enjoy but do not tell anyone in real life - two responses I got were either lots of sarcastic remarks from other mums at nct who had non sleepers or oh your second will be a nightmare!
I still had sleepless nights as spent a good few months having to express about 4 am or risk waking in a very wet bed!
LaurieMarlow I had huge oversupply issues - our spare freezer we got for batch cooking was full of breastmilk!
Enjoy but practice the sympathetic looks and keeping mouth shut routine! Sleep regression didn't hit here either so its not a given.
I am not smug - we did nothing except produce a baby who loves her sleep!