My periods ended on 28th September. I might have had penetrative sex (i m not sure about the penetration) on 4th October. My cycle length is 33 days. I tried a home pregnancy test on 25th October and also on 2nd November. Both were negative. Could I still be pregnant? My doctor has asked me to take t regestrone 5mg 3 times a day for 3 days. What if I m still pregnant and take the tablets? What are the side effects of the medicine even otherwise?