Oxfam 100km trailwalker-anyone here doing it?

Hi guys,
I'm registered for the Melbourne 100km trailwalker and have been training with my team for months (for those who haven't heard of it, this event is pretty much 100km of a mixture of flat and strenuous treking without sleeping overnight- our goal is to complete in 26hrs) I've just discovered I'm 3-4 weeks pregnant and the event is only 2 weeks away. Obviously I'll be getting advice from my Dr on whether I should still do it but wanted to see if there's anyone else here planning on doing it. Another concern is Ill only be 6 weeks and not ready to tell my team mates who are mainly co-workers. I'm thinking of faking an injury 30kms in and telling a physio at one of the checkpoints to pull me out of the event. Also I'm peeing about 4 times an hour and we'll have about 2-3hrs between each toilet stop-eek!!! Looking for some support and advice. Thanks!