Any tips for exercise around the pelvic area ?

I know this sound wierd but, I’m 37 weeks pregnant and I’ll be having a vaginal birth but I have trouble with keeping my legs wide open I don’t know why but it’s just where my pelvic area is , it’s sore when I try to keep it open , even when I went to the hospital they had to do a vaginal test and I couldn’t keep them wide open the midwife was so mean to me she kept moving my leg down to get them wide open enough it was so embarrassing 😩 does anyone know any good exercises to help my pelvic bones to be more felixable and better ? Anyone know what can help please ? Xx