My 1st did not sleep during the day or night. She would nap during her marathon nursing sessions. If I moved her, day or night, she would wake up. Sooo, I ended up holding her and sleeping in the glider most of the time.
I dreaded the nights. My husband would be asleep and I would be pacing the floor doing all I could think of to get her to sleep. She would cry and cry and cry and then sleep in my arms, then start over for about 2-4 hours between midnight and 4 am. It was dreadful. I thought it was something I was doing.. and partially it was. She was diagnosed with acid reflux and some of the foods I was eating, in excess, were causing it to be worse. I cut out all dairy, broccoli, grapes, and tomato sauces.
I also figured out that this is normal and they do regulate with a little help at around 1-3 months. My 1st did not sleep through the night until she was 3 1/2. My 2nd had the BAD night and day mix up the same as the 1st. From the day I brought them home from the hospital, but he was much better after 1 month. He started sleeping 7 hour stretches at 4 months. I was AMAZED and kept checking him to make sure he was breathing.
All babies are different and all babies this young do not need a strict schedule. Let them be babies in 'the 4th trimester' and the parents sleep when the baby/ies do. All parents are sleep deprived and the 1st month or 2 usually feel unbearable but it gets much better.
Good luck and cheers to the new baby.