Why am I getting groin rash 😖

It’s not that itchy. I don’t have any stds that I know of as of January when I was treated for chlamydia and trich from a previous partner. I only have slept with my bf of 6 months and we don’t even have sex very often maybe once or twice a week. And this past week I developed a rash on my inner upper thigh/groin area. An ER Dr did the woods lamp test and said it was a yeast infection possibly from sweating and tight leggings because it glowed like fungal infections are supposed to. gave me some cream and over the week it doesn’t seem to be helping and the rash actually spread to my outer vagina , and onto my trunk of my body. I seen my regular Dr today. She was stumped at first but the male Dr said it’s Erythema Multiform. But that is caused by herpes virus which the ER Dr ruled out that it wasnt herpes because of the woods lamp test and the way the rash looks. It’s more dry scaly, not blisters like herpes is. My dr today said it’s not contagious or anything cus it’s not producing any puss but I still feel like I am. No one around me has any rashes that I know of. I haven’t changed anything. The only thing I can think of is last week I worked and got really sweating ( I have an apron belly so I get sore skin there sometimes from sweating, thought that’s all it was)

I’m just so annoyed with it cus I’ve never had any issues in my genitals before or skin rashes ever in my 33 years and now I keep having issues down there and it makes me look gross to my boyfriend. And I’m also 17 weeks pregnant. Like I didn’t even want to tell him for fear he’d think I was cheating or something even tho I definitely am not. Or judge me for my hygiene or something even if I shower everyday. And I’m not trying to accuse him of anything either. But I just don’t know where or how or why this is happening to me right now.

I guess I’m just trying to ease my mind that it’s not an std or anything contagious or very serious and that it’s really just a weird yeast infection or something and cus I’m pregnant I’m more prone to infection. Even tho the drs don’t think it’s an std, the internet keeps saying otherwise and it’s freaking me out. Anyone have any sort of experience like this or know anything about skin rashes?