TMI but need help ASAP!

I’m on my period and I noticed a rash between my groin and thigh area. The crease? It’s a few red spots and a red larger flakey spot. I haven’t had anything like this before and I haven’t engaged in any sexual activity to cause something like this. The only thing I can think of is that a few days ago I started wearing pads of a different brand than I usually wear. Could that cause a rash or irritation?