Could it be digestive pains or constipation? They can be suprisingly painful at times, like stabbing pain and take your breath away. I've been getting them a lot over the past few days and they're always starting out on my side, by my hip.
Unfortunatly there isn't a lot a doctor is likely to do. I went to see them about strange pains at about your stage. She felt my stomach, listened to babys heart beat, checked for a urine infection and took my temperature which was a bit raised and said come back if I'm still worried.