Hi there.
Pressing or prodding you're belly cant harm the baby or you're pregnancy. Only if you thump it will. More likley it will annoy him/her if there trying to sleep. hehe x
I was always told not to press on my tummy from 0-13 weeks. My ob still has not pushed on my tummy or messed with it at all and I am now 19 weeks so I don't know I rub my tummy and my other kids rub my tummy but we don't press on it just to be safe.
I know small poking is ok casue it says in What to expect when your expecting to gte tthem to move. I asked my OB firstt though. Sharp blows will hurt but your uterine is a big muscle and very protaective. ALso midwives will slap your belly around the end to make sure you ahve enough water. If you put your havnd on one side then slap gently the toher side you will fell a wave. THe baby does nto seem to mind most of the time.
I know a lady on another forum who had a bad experience with her ultrasound and the tech pushed and she saw her abbies head boucing all around and that is not good and she is so worried. I will put little pressure to feel movments but not hard as he is still little (20 weeks tomorrow) and don't worry. I would not let a child poke you hard though of course and like the other poster said not in the first trimester as things can be hurt or mc easy then. Not been told that but my maternal instincts.
Oh yeah and I know they do this thing to turn the baby around if it is breech at the end but hat is done with us so if done right by a perfessional it is ok.