Constipation is incredibly common during pregnancy; in the 19th century, some people called pregnancy the Disease of Constipation. The good news is on of the remedies and treatments that you might normally use for constipation are still safe in pregnancy. You should start by increasing your water and fiber intake. Many women will add daily use of MiraLAX or a generic equivalent to their diet. This is a gentle agent that is non-stimulating and safe to use during pregnancy. If it’s been a few days (for a week) since you went, you may need to stimulate a bowel movement from below. Try using a Dulcolax suppository, and if this doesn’t work you can repeat it in two hours or so.
If these over-the-counter remedies are not helpful, talk to your doctor.