I second the vasovagal reaction thing. I passed out at my (one and only) Pap smear that I've had so far, and I actually have passed out more than once by just talking about Pap smears. I am utterly terrified for the whole birth experience and even for the cervical checks. I already get dizzy almost to the point of passing out when I even think about giving birth, or getting a cervical check, and I'm definitely nervous that I may actually pass out when the time comes.
35 weeks, because he'll be doing the gbs test anyway, so it's whatever to me. I'm usually a 2-3 by that point. I like to know, I guess. But if I'm not having constant contractions, I'll decline others after that appointment because I don't want to be disappointed with "lack of progress". I think it's a mind thing for me. And my checks have never hurt.
I had a few cervical checks towards the end of my last pregnancy, especially since i was two weeks past the due date. After the first one, I remember trying to psych myself up for it, closing my eyes and trying to imagine that it was my husband and that there had been adequate foreplay ... didn't work.
My OB doesn't do them (preg now with 3rd). The only time I've had them was when I had spotting and when my water broke. Some times they hurt like a motherf***er but sometimes it wasn't painful at all.
Re: STMs: When do checks for dilation/effacement start?