we bought a repo just over 2 years ago now.
we had a month interval between completion and moving in, which was essential. gave us time to ensure all utilities were connected and up and running (we even managed to have functioning broadband prior to move day).
the biggest problem we had was we knew the central heating hadn't been drained down prior to the 2 or 3 years the property had been vacant - there were clear signs of water damage, and knew there were burst pipes in the eaves. the day after completion, we had a team of plumbers come in to the property to rectify the multiple problems we knew would occur the second we switched on the mains water. they had to repair or replace about 10 sections of pipework, and i cant tell you how upsetting it was to see water pouring from the leaks through the ceiling of all 3 floors, and every time one leak was repaired, another one sprung up!
anyway, all leaks were sorted, and we then had to repair the water damage in the affected parts of the building - which meant removing damaged plaster, treating damaged timbers, replastering, reflooring in parts.
we also took the opportunity during the month period of moving in to get all electrics inspected and repaired as necessary (and there were indeed some dangerous electrics) as well as ensuring boilers were working, repaired as necessary and serviced, as well as making sure we had hot water and heating. once oil was delivered (oil fired boilers) i basically left the heating on pretty much full, with some window open, for 3 weeks in order to dry the house out.
the month before moving day also allowed us to get all essential white goods delivered prior to us moving in (cooker, fridge, freezer, washing machine etc).
of course, you could move in and everything be absolutely fine from day 1, but i would strongly suggest you make some alternative accommodation arrangements for you and your family for at least a week or two, just to give yourself the opportunity and peace of mind to make sure all utilities are working, and more importantly SAFE, not least of all because you are pregnant and have a baby. please take particular care with regards to electricity and carbon monoxide.