I'm not sure what "open" means, but things change dramatically in the first year, much less the first three months. At 1, 3, 6 and even 18 months, I had a gaping hole that was always visible below my labia. (That sounds like it might be what you're worried about.) I also had a ton of swelling. Around the two-year mark, when the swelling had finally fully disappeared, the outer labia draped down to cover the vaginal opening, and the vagina itself started looking like a mostly closed slit except when I'd just taken a dilator out. So give it time.
(I also had a gynecologist think I was cis in that first year, so I'm another vote for "cis vaginas and vulvas vary a LOT," too.)