Is it common to have trouble concentrating during pregnancy?

YES it is!: Especially if, as is also common, your stress level increases with problems at work, with a partner or family, with children you've already had, and the time demands and financial burden(s) of having children. Pick up some self-help books on time management and managing stress and talk to your doctor about it!

Could be : Pregnancy can be stressful , specially if u r very young , has limited resources and no support system.