Hello friend, With a normal 28 days period, which started on 6th September, you have less chance of getting pregnant by the unprotected sex on 28th. Also because you have taken the pill, it is not possibly going to happen. Only because your period has not come regularly this time, you need not get worried. The main reason is that you have taken the pill. It contains hormones. This will disturb your orchestration harmony of hormones and will get re established only after one or two periods. You did not say much about your sex. Was it with your regular partner? You had any mental disturbance during or following? Because such psychological reasons also can make problems in the regularity or rhythm of your periods by intervening the hormonal activity. Pregnancy can be confirmed or ruled out by blood or urine test 7-10 days after the possible day of conception. That means now you can very well do the test and take next steps accordingly. I am a Homoeopath and so will not suggest any medicine to terminate pregnancy because Homoeopathy believes in treating sick individuals and there is no Homoeopathic remedy for inducing abortion. Personally I will not support a foeticide also. With Best Wishes, Dr C. J. Varghese, Homoeopath. drcjvarghese@gmail.com.