Im on microgynon 30 and have been for 4 months... i take it every day at the correct time; except for once were i forgot to take one but took it the next day and had my period the week after (as it was due). in the last month i have had sex once (without a condom) and i have taken the pill properly... but i was due yesterday and i am normally clockwork and there is no sign of it coming on.... really do not want to be pregnant. please tell me there is another explanation.