Here are some links about it:
http://www.mamasource.com/mamapedia/kids-by-age/pregnancy...
http://www.birth.com.au/Info.asp?class=67&page=27
Each pregnancy is different. If you feel that butterfly sensations or like bubbles/gurgling in your tummy, that is the baby.
The reason that a baby is felt more in later months is basically because as the baby grows, there is less space for the baby to move around in, thus, you feel the baby's every movement.
I felt that preliminary "movement"/fluttering in my tummy from about 4 months...
No, boys are not 'lazier' nor girls. Again, each pregnancy is different and the 'personality' of the baby. And what you eat can affect them too and their movements in your tummy. Certainly no caffeine!
My girl was more active at night and kicked more. Hard. She was also more active whenever after I ate. My son although active throughout the day, did not kick me as hard, and I could tell when he was sleeping...he was more regular about that and even after he was born.
Congratulations and all the best,
Susan