If the period is missed and pain is present, you need to have a vaginal scan to see any pregnancy inside or outside the uterus, also get a urine pregnancy test done. Most cases are diagnosed by these, but some may need a laparoscopy. If the pregnancy is in the tube, it may be ruptured or intact. Still but in the tube. In most cases surgery is the treatment- laparoscopy for the unruptured and open surgery in ruptured ones. If this is a precious baby, or conceived after problems, and you may want another try, sometimes medical treatment is done in unruptured ectopics for which you need get hospitalised.