Are there any US sites like Mumsnet?

[carseatgreet]

Just that really.
I've recently moved to Massachusetts and I'm pregnant and just feeling a bit out of my depth.
MN was a really helpful resource and I feel like something similar but US/New England centric could be really useful now but I'm not having much luck finding anything?

I don't think so - that's why we lurk here babycenter has a community, and there's probably a local Facebook parents group for your area - those are great for buying used goods and finding out what Obgyn/ Pediatricians are recommended.