Do I have to label my own products as advertising on Instagram?

Generally no, provided the commercial purpose of the post is already obvious. When you, as the owner of your own online shop, post a photo of your own collection and your account, bio or shop link makes it clear you are displaying your own business, courts do not require an additional 'advertisement' label. The position differs once the post reads strongly promotional—with discount codes, direct calls to purchase and links to your shop—because the line between your content and traditional advertising then blurs. When in doubt, check your account: if it appears clearly commercial to others, you are on the safe side.