I'm at 36 weeks +2 and until yesterday amazingly I have had no backache. Yesterday I suddenly got sharp pains in my lower back (pelvis) and groin that got worse when I walked. Today it is not so sharp but there is still a pain in my groin (left side) when I walk and an ache in my lower back. Are these just normal pregnancy sensations that I've been lucky not to get until now, or should I be worried? Advice please!