Aw mama, that sounds so uncomfortable talaga! A few of us sa circle went through something similar, one friend said her rashes were from hormonal changes and the stretching ng skin, but hers spread din like yours kaya best to check with your OB just to make sure it's not something else na kailangan i-address, like PUPPP or a fungal thing. Meanwhile, try wearing loose cotton clothes (I know, puro damit na yun na haha), keep the area dry, at avoid anything too warm or irritating sa skin, some moms swear by staying in air-con or using a fan. Hang in there, yan lang usually pero definitely worth a quick call to your doctor para sa peace of mind!