Running a marathon??

Hi everyone! 
I am running a half marathon at my 2 month mark. I'm feeling good about it as that's only 3 weeks away. There is a full marathon at my 6 month mark... am I nuts to even be thinking about running it?! I'm an avid runner and I'd love to accomplish that feat. I'm super looking forward to being a mom so that's obviously my main priority but I was just wondering if anyone else has done it or seen it be done? Thanks!