What is this 😳😳😳😳

Pip β€’ Pregnant with a little boy β€’ c-section is booked for 4th July 2016 at 8am ✨
Need advise. I'm 35 weeks pregnant, today I've had some discomfort and pains. It's like stitch which you get in your side when walking, that's the only way I can explain the pain but it's down under my bump, in my pelvis and vagina, it's like a really sharp tightening feeling which hurts. Also have aching pains down my legs and sometimes in my back. Has anyone ever experienced this?