Masturbation and cramping

Marie
I'm 6w3d and I have been cramping every time I orgasm. Is this normal? Has anyone ever had a miscarriage because of it? I had a miscarriage back in November and now I'm terrified of doing anything sexual with my SO, so I resulted to self pleasure and now I'm cramping. Nothing crazy or painful but it worries me. Any advice would be helpful. TIA!