Should I be worried about bruising lower butt cheek?

You should ask your plastic surgeon about this as buttock implant surgery recovery can be difficult.Kenneth Hughes, MDBeverly Hills, CA

It is difficult to know without at least seeing a photograph and knowing exactly what you had done.  I don't usually see much bruising if I do implants alone, but I usually do them with some fat grafting and then minimal bruising is common. Contact your plastic surgeon and express your concerns with them as they can advise you best.