Hives

So for the past 4 days I've randomly broken out into hives. I'm not allergic to anything and I haven't done, touched, used or eaten anything new. They come and go and they're almost everywhere on my body but worse on my hands and feet and it itches and burns and they get swollen. It was so bad I had to go to urgent care and all they did was give me meds and say oh yeah you could be allergic to something. It happens when you get older. Somtimes you just get allergic to stuff. So my ob just said to do anti allergy meds. And the 3 meds they gave me have been working but it's minor relief. So I'm just wondering has anyone experienced this during pregnancy. I was looking stuff up and I saw something called pupps . What are some tips.?