I have no medical expertise , so my suggestion is FWIW

A pregnant woman should try avoid ( as much as possible ) getting sick and having to take medications. So, it is not a bad idea - IMHO - to take a few vitamin supplements and maybe some garlic (or garlic pills) to help make your immune system a bit sturdier. This is true especially during camping trips where you get less sleep, eat food of lesser nutrients and get exposed to more cuts and bruises ( meaning : more chance for harmful critters to attack your system )

From my personal experience , vitamin supplements are very helpful in stressful times.
YMMV