that whenever I stand up from sitting for a while (like half an hour or longer) my tummy gets hard?
I'm pretty sure its a braxton hicks.
There is never pain anywhere but it is a bit uncomfortable.
Quoting 11 weeks with #3!:" sounds normal, braxton hicks can happen anytime or for any reason. If it doesnt stay hard or turn into labor I wouldnt worry about it. It sounds like your change in activity is just triggering it."
It gets soft again but normally I'm distracted (with DS, or school work etc.) so I don't know how long it takes.
Its not timeable either.