Tough Mudder while 10 weeks pregnant

Sarah
Hi all, 
I have just found out last week we are expecting our 2nd baby. I am 4 weeks 6 days today. 
Last year a team of 6 of us have signed up for Tough Mudder (in the uk) I am still planning on doing it as I'll be 10 weeks pregnant. I am generally fit and healthy and try to regularly exercise (when no1 lets me). 
Just want to know if any of you have done an OCR while pregnant?!