I have had to take 3 plan b (leviciten i believe its called) pills in the last 3-5 weeks. i have had 3 periods in the last month, and this last cycle is current and lasted 3weeks. i have a dull pain on the left side of my bladder. what do i do?

Best to be examined by your doctor. However, if you do not have one, Planned Parenthood would be a good option for a proper examination. Also due to sexual activity and desire not to get pregnant, using regular birth control would be better for effectiveness and your body and PP can handle that too. The current period lasting 3 weeks is itself a reason to be examined asap. Take care of yourself.