Hi there,
Any sexual act can result in pregnancy no matter you are in which phase of your menstrual cycle. Pregnancy can occur if sperm comes in contact with egg. Though the chances are high if you are in your ovulation days. Missed period is the earliest sign of pregnancy. If you miss your periods take up pregnancy test. This is merely an advice and not a substitute for clinical examination. It is suggested to consult a gynecologist and get evaluated. Hope it helps.
Good luck and regards!