It's so hard knowing what's normal and what's not in pg isn't it? You could have round ligament pain, I get it on either side and it's like stabbing/pinching pain. When my belly was crampy (above my pubic bone like AF pain) I was worried as I didn't know if that was normal. I've learnt to tell the difference between crampy pain and ligament pain now. The shooting pain down your leg sounds what I get too, mine shoots from my lower back into my bum and then down my leg. Lovely!
The other thing I was going to tell you is that when I'm constipated (which is a lot of the time) I get crampy feeling in my belly from that too. When I have a bowel movement, the pain goes sway so I figure it's from the poo being stuck (sorry TMI!!). Has your pain improved in any way?