Hard to say what it could be without examining it, but based on what you wrote, it could be a stitch or a spitting suture. Don't pick at it but go see your surgeon as she/he will be able to determine whether it is something that needs to be addressed immediately or will subside as you heal...
You do not actually have to be in possession of your documents. If you don't even know which manufacturer was used, that can be found out at surgery. Say you know nothing except the actual date of your surgery. You have surgery, the implants are removed. They have identifying...
Please follow up with your Plastic Surgeon regarding your concern. Photos and examination are needed. Please make sure to follow the post operative care guide your PS provided.