Advice from Military Moms/Tough Moms

I found out I was pregnant just a few days ago (4wks today) and have been scheduled for months to leave this upcoming Friday to go out to the field for the next two weeks (pregnancy weeks 5-6) where I work as a Training Instructor. I've done this for the past couple years and LOVE it. However, it is somewhat demanding, up at 0230/0300 most days, chugging down a couple warm RedBulls, then out in the cold/sleet/rain for ~12hrs, eating primarily MREs. My command had a discussion about whether or not it is appropriate for me to attend any longer and, ultimately, left the decision up to me. 

I'm torn on whether to go as planned or stay behind.  They will not be undermanned without me, so my absence will not affect the overall mission. However, it is an excellent experience and contributes to my promotions and career developmen. I was going to be in a slightly different role this time and probably would be inside a bit more, though the hours would be the same, it'd be less LandNav, less hiking, less gear, less jumping in and out of Humvees.   

I won't be chugging down caffeine anymore, so I'd be a bit more tired than normal. MREs are definitely NOT the best thing to be feeding babies, but I'd be taking my prenatals and I  often drive into town with someone nightly and go have some real food- so I don't think that's a huge deal.  Last year I got a stomach bug and would have to run over into the bushes every so often to throw up, but then ran right back into the thick of things.