Itchy rash, back& shoulder (one side)

Brit-26👼🏼🤰🏽🌈

Hi, so I’m wondering if anyone knows what this could be, it started yesterday and is since getting worse. It’s on one side of my back. There’s a cluster of them at the top of my back & a cluster on my shoulder (same side) and then a few dotted up and down my back. They’re very itchy but not sore. I’m 9w6ds pregnant but never suffered with anything like this. Thanks