I'm in total agreement with all that DG and Rogue have said. You really don't know until you've missed your first period, and even then, it's not like you'd rush out and buy a test if you were a day late. I was extremely regular for the most part, but was late once or twice when I was trying for children without being pregnant.
I've had both a Cesarean delivery and what they call a VBAC - Vaginal Birth After Delivery. The Cesarean was not scheduled, but Teengirl was having deceleration of her heart beat with each contraction, and since I was "older" my OB wanted to err on the side of caution. You feel nothing past the pinch of the spinal, and since you;re generally draped, you see nothing until they hold up the baby, which is surprisingly quick.
Vaginal birth for me was fairly uneventful. I was in actual labor intermittently. I began in the late afternoon, it stopped at around midnight, and resumed at about three am with a vengeance, and Teenboy arrived a little more than six hours later. I had a late epidural (9.5cm dilation because my OB for that birth was an idiot and waited until shift change to call for the epi). But he was still an easy enough birth as things go. Yes, I yelled, because I focused on pushing better when I yelled. (My OB frowned at me and I asked him if he wanted to give it a go.) Yes, until the epidural, there was pain, but it never hit unendurable for me.
As far as the physical experiences of pregnancy, again, it varies with every woman you talk to. I had no morning sickness with Teengirl, gained around thirty pounds, and was not ungainly. With Teenboy, I had morning sickness from about 2 months to 4 months along, and I was fecking huge, although I still didn't gain more than thirty-five pounds. It was ALL belly, to the point where people were asking me if I was having twins. But I was fairly energetic through both pregnancies, and can't say that it was terrible, although I could have done without the awkwardness in the last trimester of Teenboy's gestation.