Mud Run when 9 weeks?!?

Abby • 👶🏼 Danny Lee 7/22/17 👼🏼 12/12/17 👶🏻 Deagon Levi 12/17/18 👶🏼 Daxxen 8/15/2020 Army wife 🇺🇸 Breastfeeding Mama 🤱🏼 Natural Birth Survivor x2

So my brother signed me up for a mud run to do together (he doesn’t know I’m pregnant yet) and I’m not sure if I should do this mud run or not. Has anyone done a mud run at 9weeks? I enjoy running and lifting so I’m not scared of running just the obstacles maybe