Hello,
This can be due to papular dermatitis of pregnancy which presents as an extremely
itchy rash consisting of red, raised spots
that look like insect bites. this
rash can erupt at any time during pregnancy and then spots continue to appear until childbirth when they clear rapidly. Apply some calamine lotion on the rash and consult a doctor for steroids prescription if the rash persists.
I hope it helps. Take care and regards.