There are three forms of protected IP in most places:
1. Patent, which protects 'designs of things'. It's unlikely such a connector could be protected by patent.
2. Copyright, which protects 'creative works'. The datasheet of the connector is protected by copyright, as are any design files created by the manufacturer, but creating your own implementation is not.
3. Trademark, which protects 'brands', and likely doesn't apply here at all unless you start trying to sell it using their branding.
So I don't see how this could possibly be infringing. Most places also have some exceptions or more leniency if any potential infringement was for the purposes of interoperability, as is the case here.
But I am not a lawyer, and as others have said, you can generally be sued (or more likely sent a cease and desist) for anything, whether you are in the right or not.