Itchy rash 17weeks

Amanda.
So I'm 17weeks with my 3rd child. About almost a week ago I started to develop itchy little red bumps on my legs, thighs, butt and sporadically on my arms.. It's really itchy on my butt and legs... I don't have an appointment until the 30th but some things I read about rashes on the internet makes me nervous..I have not used any different soaps or detergents and it's not bed bugs..any advice?! Anyone else having this?!