itchy labia?

I’ve been having irritation and itching in this area of my vagina (the yellow highlighted part) for almost a month. i’ve been go to the doc to get tested for yeast and STDs but it all came in clear. It’s not constantly itchy it’s more on and off but it’s super annoying. Maybe it’s my soap? Any have any gentle soap recommendations for the vaginal area? or have any ideas about why I could be so itchy for so long??? please help