Hello, Thanks for submitting your question here. You are on sysron N for 4 days while you are also suspecting you are pregnant. A pregnancy could only be detected after a missed period by doing a urine pregnancy test. Otherwise a hormone termed betahCG measurement could give you a clue for a possible pregnancy. An USG is unable to detect pregnancy before 5 to 6 weeks of gestation. Now,sysron N contains a synthetic progesterone. Though pregnancy needs a progestetone often,but a natural one. However, a 4 days course of sysron N has no such effect over pregnancy, if it is at all positive. I suggest you to stop the sysron N now and perform a pregnancy test after a missed cycle. You can proceed then your GP if pregnancy test appears positive . Sincerely Dr Sanjoy