I was reading somewhere (sorry for no reference) that your rash like symptoms can occur during pregnancy. If you live in the US then I suggest your doctor was hosing you. Or else it could be bug bites, in which case I'd suggest you try cleaning your bed sheets, if you haven't already since you've started having these symptoms.
Other causes include STDs and (in my own opinion) it could be an allergic reaction. Sorry, I didn't read on to see if the allergy symptoms were included in the article of which I had gathered the previous information from.
I hope this helps... I have a similar issue but it's only located on the right breast. I used Glysomed lotion, which has stopped the itching for about an hour now.