I know when I went to my 20 week untra sound he was asleep so the tech kinda jabbed at my tummy to get him to wake up. He was stubborn but finally rolled so if I ever feel like I haven't felt him in awhile I will push on my tummy a little in different spots to get him to at least move (:
Yeah I was like that too, I used to put my cell phone ringer against my belly to try to wake her up enough to kick. I tend to be pretty active too, so probably just wasn't really noticing. If it makes you feel better, the last few weeks of my pregnancy it's been unmistakeable, she's been beating me up over here. :)
I'm not sure about the BH but I know I always get uneasy when I try and count my baby kicks. Because he seems so much more active at night when I'm putting my 3 yr old to bed and seems so much less during the day. I've been told it might be due to more activity during the day that I don't really notice it as much
From what I understand everybody has Braxton Hicks, but some women don't feel them. That's probably why you've never noticed them.
For kick counts, you're supposed to basically choose a time every day when the baby is usually active and lie down for an hour and record how long it takes to get to 10 kicks. That way if the baby's pattern changes you'll be able to tell. My doctor didn't tell me to do it until I was into the third trimester, you can ask your OB when you should start and how you should do it.