It could be something called spd you need to speak to your doctor about it. It hurts like hell but can be treated to make it less painful and if left untreated will just get worse
Oh okay I thought you were describing your height! This happened to me around 5 weeks as well. I'm 11+2 now. My doctor told me it's from your uterus growing. It made me really worried and I actually went to the ER because of the pain. I must add though that I didn't have abdominal pain. I had the back hips and thighs pain though. It went away after a week and a half. If the abdominal pain persists I would call your doctor to make sure everything is alright. But it sounds just like a growing uterus to me!
I'm 33 5/7 weeks but I have never experienced this not even with my first pregnancy