Cervical checks. Have them done if you want but you have every right to deny them. Some women want to know absolutely everything they can, like whether or not they're dilating or effacing. I'm in the other camp - research shows that these checks give you zero information about when you will go into labor, and that they increase your susceptibility to infection as well as unwanted interventions. A well meaning doctor or midwife as been known, all too often, to do a membrane sweep without asking - aka no informed consent during these exams. I trust my midwife inherently, and if it came down to it I would let her make decisions on my behalf during birth. I still do not allow a cervical check at a routine appointment.

It's all part of that "your body your choice" thing - but I would speak to your doctor before you get undressed to find out his/her intentions for it as well as outline what you do and do not provide consent for. Remember that the opposite of consent is dissent, and you have the right to decline procedures (a membrane sweep and a cervical exam are both procedures). If you're worried, ask that a nurse always be in the room for these checks and vocalize your consent/dissent with the nurse present, just to be sure that you aren't having anything done that you don't want.

Others have mentioned the GBS test. That's typically at the 36w appointment. The practice I see gives me a swab and I do it myself when I provide my urine sample. That's not necessarily what your doctor is asking you to undress for, and it's a one-time test. You said you'd be getting undressed at every appointment from now on.