Dermatologist. You should certainly have your OB have a look but this may require a dermatologist. There are some dermatologic conditions that can occur specifically during pregnancy. A dermatologist can help to determine what is going on.
If you're asking.... ..Whether you both can occur at the same time, yes. Most rashes peel as they go away, the same way a sunburn does. You shouldn't assume your rash is infected, though, unless a culture has been taken and is positive -- in which case you may need an antibiotic.