BF,
I know the guilt. I've felt guilty too but just remember you did not cause your mc through playing on kids equipment. look at all the celebs.. they jog, run and do allsorts of things. Nicole Kidman was still jogging/running at 5 months preg. Angelina Jolie was carrying around Shiloh and Zahara to the day she popped out her twins. I think Mother Nature has designed our bodies to protect our bubs when we do heavy lifting or runabout.