Registry gifts

we got a really nice gift in the mail from our registry last night (one of our china vegetable bowls), from a couple that is coming to our wedding. it was totally unexpected and now i'm wondering if that is our wedding gift??

i checked my registry afterwards and a couple of more things were bought (2 cutting boards and our cake knife set) but we haven't received them yet.

do i send a thank you card now to the couple who sent us the china bowl?? or wait till after the wedding in a couple of weeks?? i hope it really isn't our wedding gift lol.