If you've had other checkups, like 4 weeks or whatever, I would guess you don't need this one. But otherwise maybe.
My midwife checked my fundal height with each PP checkup, and at one of them - 3 or 4 weeks PP, can't remember- my fundal height had risen and she was able to catch an infection right at the start, and with antibiotics we were able to get rid of the infection. The nurse I saw after my midwife sent me in told me that left untreated a PP infection can be life threatening. My only other symptoms besides a rising fundus, at that point, were feeling more tired, and 'off'.
I don't see any reason you should have an internal, unless you feel like there is something you want checked.
Christian wife, busy happy mama to 6yo DS, 5yo DD, 3yo DS, and 1yo Ruby! ICAN leader, tweeter, nerd.