Shooting pain in butt - 18 weeks

I have a shooting pain that goes down my butt. 2 weeks ago it was on the right side. I couldn’t even get out of bed to go to the bathroom without screaming. The doctor said it was probably something I did at the gym. It went away. And then this week I have the same pain in my left side. Does anyone know if this is related to pregnancy?! I’m 18 weeks. I’m very active, in shape and still waiting on my baby bump so it’s not like I’m carrying around a bunch of weight 🤷🏼‍♀️