What Causes Irregular Periods With Heavy Clotting?

ive had my period for 15 yrs. its always irregular. i get it every 10 to 20 days. on a few rare times it was 6 to 7 wks in between. i always have major cramping and heavy flows, clotting. the periods last from 7 thru 10 days. i take pamprin to control the pain but sometimes it doesnt even work. i am now 30 & havent had a period in almost 2 mos. i just recently took 2 pregnancy tests & both were positive. i took it because i hadnt ever gone this long without a period. could i really be pregnant? with all my problems i figured i was infertile. i was always too scared to go to the doctor and i have no medical insurance. i have been feeling tired, pressure in my lower abdomen with some sparatic mild cramping. i have been urinating frequently. my breasts do feel swollen. but i havent had any spotting or vomiting. i cant have a kid because of my financial situations. i dont know what is going on. years ago some friends thought maybe i had cysts or endometriosis. but if i havent had a period in 2 months then that doesnt explain much. i have read about abortions, either suction or pill but both seem very painful & awhile to get back to normal. any help or advice would be greatly appreciated asap. thanks