Confused

I had sex on the 15th of October, been diagnosed with ovarian cyst on the two ovaries and fibroid, had a short and painful period between 28-30th of October, the first 2days were heavy and my period usually last 5days. I had an ultrasound on the 4th of November and nothing was seen, taken 6 home PT and they all turned out negative, I started taking birth control on the 2nd of November and I spotted blood on the 16-18th. I started having cramps on Friday and I tested on Friday and it came out negative. Can I be pregnant? I'm confused please