Rash in armpit

So I’ve had this for about a week and a half now. I thought it was from my deodorant but it’s only on my right side. I’m 11 weeks pregnant and I’ve never had anything like this before. I stopped using my deodorant (ew) 🤮 and started taking Benadryl. It didn’t help. So I went to my doctor Friday and he gave me a steroid cream and fugal cream. He didn’t know what it was. I’m just kinda worried it’s something worse. It doesn’t itch like it used to, it’s gone down a lot, but it seems to be spreading. I guess my question is..has anyone had anything like this before?

Before cream:

After cream: