Scared that I might have a std

So I’m getting a std test on Monday because I have symptoms of my butt pain and sore vag. I have no smelly dish charge or burning down there. But I’m so scared I never been tested. I don’t wanna tell my fwb that I’m getting tested because we used a condom and I don’t want him thinking I’m dirty so what should I do? How do avoid having sex with him without telling him I’m getting tested.