I had a really similar reaction to something when I was pregnant with Harrison... I'd previously used it before becoming pregnant so didn't think it would be an issue. I would end up in tears because of the itching. My DH got me some Polaramine and it worked brilliantly. It took about a week of no scratching for the itchiness to go away.
Maybe pop into the chemist and grab yourself some Polaramine to stop the itchiness and then go see a Dr if you're concerned.
I hope it goes away soon