Have PCOS. Had surgery to remove tumours. Have unprotected intercourse, spotting after intercourse. Pregnancy test negative. Pregnant?

HELLO, ME AND MY BOYFRIEND HAVE BEEN HAVING UNPROTECTED SEX. I HAVE POLYTHEISTIC OVARIAN DISEASE AND HAVE NEVER BEEN PREGNANT. I HAD A SURGERY IN 2009 TO REMOVE 3 GOLF BALL SIZE TUMORS. DOCTORS SAID I WAS GOOD TO GO AND HAD KIDS, BUT I HAVEN T HAD ANY LUCK. NO I AM FEELING ALL OUT OF SORTS, LIKE CONFUSED AND FLUSTERED. THE LAST DAY OF MY CYCLE WAS THE 20TH AND I HAVE STARTED SPOTTING ON THE 25TH. MY CYCLE LASTED 7 DAYS LIKE NORMAL. I FEEL AS THOUGH I HAVE A YEAST INFECTION ON TOP OF THE LIGHT BROWN RED DISCHARGE AND WANT TO KNOW IF THIS COULD BE A SIGN OF PREGNANCY. I DID TAKE A TEST AND IT WAS A CHEAP ONE, NEGATIVE. THE ODD THING IS THAT AFTER ABOUT 30 MINUTES IT STARTED TO FORM A TAB BIT OF ANOTHER LINE, BUT IT NEVER MADE A COMPLETE SECOND LINE.