7weeks pregnant .. small pain at top of pelvic bone on right side . should i b worried ?

Yes: Without more info the first thing an emergency physician would want to know is if the pregnancy is in the uterus where it belongs. An ectopic pregnancy is a pregnancy growing somewhere else and can be life threatening to the mother. An ultrasound will provide the needed information. Go to the er or see your obstetrician right away. Other causes may be simple stretching pain, a miscarriage, or uti.