What do I do if I have extreme abdominal pain while months pregnant?

41 and in pain? It would help to know the gestational age in order to list possible causes. Nevertheless if a pregnant woman of any number of months has pelvic or abdominal pain, an OB or maternal=fetal medicine doctor should be informed immediately. It might not be a major problem with the pregnancy. However, doctors often want to talk with or see a mom (over 40, in particular) if anything out of the ordinary.
See your OB MD. See your OB md as soon as possible, as extreme pain can represent serious pregnancy problems.