Sorry for your losses, their are pros and cons to both really. I told my Mum straight away last pregnancy and a couple of very close friends and family around 6 weeks. We told work when things started to go wrong as we needed time off for extra appointments and grieving. We never got to the public announcement stage, we lost bub at 8.5 weeks. I don't regret telling a few select people, I needed the support although I found some accidently said the wrong things at the time (meaning well of course). Personally, I think I'd find it awkward if I'd done a FB/Public annoucement and have everyone giving me their input.
This time we told the same people although I kept it quiet from family except my parents until our 8 week scan. I'm now 14 weeks and have had our NT scan, planned to spill the beans publicly around 12 weeks but have been putting it off. Will be telling extended family at our Christmas get together. Now I'm questioning going public at all, word will spread eventually although I may change my mind any day now .