Travelling to Peru

Hi All, I just got my first positives today for our first pregnancy and we are over the moon!! The only concern is we are booked to go to see Machu Picchu, Cusco and a Rainbow Mountain hike next week (I will be there during between my 5th and 6th week). I am definitely going to cancel the hike but just wondering if anyone has done a similar travel at high altitude whilst pregnant??