Race C,
tummy tightening are normal, most likely is BH contraction, aka not the real thing. Unless it is coming at 5 or 10 mins interval, then its the real thing.
Do you mean rashes? Dun worry abt it, it will clear up soon. I have been having rashes ( super bad ones, all over the body...cannot slp, must scratch and scratch till i have been wearing long pants for the whole 9th months liao).
You can try to take only cold shower, apply lots of moisturer.
But be happy that you only get it at this last stage...
Cheers!