Has anyone here given OET/IELTS?

Has anyone here given OET/IELTS? I need B grade/7.5 bands in all components to apply for medicine in UK. But my stutter can get really bad when I'm stressed out, so I'll probably fail at the speaking component. And when I'm supposed to stutter, e.g Infront of my psychiatrist, I DON'T stutter. So I'm nervous about the fact if I'll be able to get a medical certificate or not. Anyone have their experience to share?