Are you having bub in a hospital? How will you get home? I don't think I'd trust a taxi for my bubs first trip... (yes I'm an overprotective mother!! Lol)
I'm also one of those "better to be safe than sorry" people, so I would get one JIC. You can get great rear/forward facing ones at a reasonable price, they are usually for up to 18kgs so I'm sure you would get some use out of it over the years!
All the best with whatever you decide darl