Had Unprotected Sex. Took Norlevo. Ultrasound Showed A Cyst.Pregnancy Test Negative. Nausea. Pregnant?

Hi, I took norlevo on the 9th of March within 20mins of unprotected sex. I had spotting after a few days for a day only. I went to my gynae on the 2nd of April, he did a pregnancy test which came back negative as well as a scan which showed a cyst about 10cm in diameter. He said he was a bit concerned as I should of had a period within two weeks of taking norlevo and that the cyst is caused by the norlevo. The cyst is blocking the view of the womb, he said if I do not have my period in the next two weeks I must repeat the pregnancy test. I was anxious so I did one yesterday, the 7th during the day but it came back negative. Its going on the 5th week, surely there would of been enough of the pregnancy hormone if i was pregnant by now. I have been suffering with terrible nausea in the past two weeks.