Pain while peeing

So since I had my son back in 2020, Iv had issues with my period. It never seems to fail every single time I get my period I get like a rash on my area. And it burns !!! It’s like I have open skin . And I change my pads and tampons regularly I never sit to long in them I pee the minute I feel I have to pee but I’m literally on day one of my period and already have a rash. Has anyone else experienced this ? What is it what do you do for it ? No I don’t have any stds or stis.