What if a pregnant woman goes into space how long will her pregnancy last?

She would abort on her way there. The pressure on her way up there would crush whatever is of the fetus.

I have never given this any consideration,specially on Friday nights.Not a criticism,just one more of my shortcomings.

i wonder if conception and pregnany are influenced by zero gravity

Assuming a normal gestation period, 9 months.

I think there will be no effect, before she is already pregnant before going to space... No menstrual cycle during pregnancy + implantation occurs in fundus region where uterus is already with will nutritive fuild...

3 days

I'm sure, on some level, experiments to discover this have occurred. From conception rates to fetal health. (They don't send men and women up together for no reason)

If all conditions are normally maintained while in space, it would take the same amount of time as it would on Earth...babies don't wear watches or read calendars.