I made a registry on registry.com. we're going to share it after the next u/s (we have to have a second anatomy due to the way baby was sleeping). I'm 19 weeks and my pants are still too big and this is my second.
I just bought maternity clothes as I needed them, I was due in February so I survived with just a couple pairs of pants and mostly oversized sweaters and shirts.
Maternity clothes I'd buy fairly soon. I always found it really difficult to get things that fit and look good, so wouldn't want to be in a situation where I suddenly was desperate for maternity clothes and had to settle for whatever I could get quickly
I would start your registry now through babylist! And i bought maternity clothes early too because i HATED the way my pants felt on my stomach and it made my stomach look odly shaped 😂