Has anyone experienced this with pregnancy sex/arousa

Hello everyone, I’m 8 weeks along and having a pretty comfortable first trimester, except this one thing. Sometimes when I have an orgasm, even without penetration I have light spotting afterwards. The blood is usually brown and the spotting lasts about 1 day. It scares me quite a bit, I’m pretty sure its not hurting baby, I don’t have cramps and my last ultrasound showed a normal baby with no bleeding. Is there any way to prevent the spotting?