Mine are slimmer than standard size (being petite and all makes buying stuff not so fun because NOTHING ever damn fits!), I measured a little quick and I am 14cm around my wrist (between hand and bump) and bracelets usually are around 17-20 cm I think (at least those I find).
No worries at all, until then you can always think about what you want Be aware though I only make bracelets with bronze coloured metal clasps/rings since I am moving away from gold/silver plated nowadays.
Checked mine quickly - cus I got curious - and I'm 20-21 at the same place. Which fits pretty well with your findings, cus it's usually very little that makes the difference for bracelets being too tight for me.
Bronze is my favourite of the three, so that fits me like a glove I'll think about it and we can talk about it again when my situation allows for such priorities ^^