Long travelling due to work

Hi all

I'm 21 wks pregnant, as part of my job I sometimes have to commute to a project which is over 200 miles away in one day (100 miles there and back), I either get the train which is 8 hrs travelling or I drive which is 5hrs driving, it used to be once a month i would visit the project now my employeer is asking me to go every 2 weeks, the journey and travelling is stressing me out and my partner isn't happy about it.

I don't want to make a fuss at work and look like I'm being awkward but I do feel it's a bit excessive and they're putting me in a difficult situation.

Any help or ideas please? Am I just overreacting and need to just deal with it, once I'm in 3rd trimester I defiantly won't continue with the journeys