I don't find it stressful, but since I never did this with my other kids, I find it a bit silly. Of course I'd realize if my baby was moving much less than normal. Especially now that the movements are getting uncomfortable. I just wait until I eat, then start counting. I always feel 10 movements in 10 minutes or less.
Personally I feel the counting your baby's movement a little stressful. I haven't been told to do it and I'm 30 weeks but if I were told to i'd be getting numbers way in the thousands b/c my baby is so active. He is most active right before I even know i'm hungry so that's my cue to let me know that my stomach is about to tell me i'm hungry. I've felt him many times moving around for at least 30 minutes to an hour constantly.
The other thing about doing this is some babies are just not as active as others. I've heard other women say that they're baby is laid back and barely move but others are like my baby and move all the time. At some point, you learn your baby and their schedule so even if it's not an astronomical number, don't be worried. Just have confidence that you know your baby and his or her schedule then you'll be ok.
Oh My God Karen, I also feel my baby hit me in two spots at once. My doctor hasn't asked me to count my baby's movements. All I know is he moves and kicks a lot!! I will visit the website EmsMom07 posted and see if I get info on that :-)
Generally speaking, you start timing at the first movement and see how long it takes you to get 10-15 movements (depending on your care provider). You do this over a period of a week and figure out a round about idea of how often your child normally moves. You can also write down the time of day you take each reading because some babies are more active in the morning and at night. For example, in the morning your baby may take 90 minutes to get 10 movements but in the evening only take 45 minutes.
Here's a website that I found awhile ago back, I posted it in the September 2010 due date forum, and the October 2010 due date forum, it explains everything that you need to know to help you keep track of your baby's movement. Hope this helps, and Congrats! =0)
http://www.baby2see.com/medical/kick_count.html