When Will I Have Menses After Taking Meprate For 5 Days?

hello doctor , from starting my periods are irregular,means 10 or 12days late.my last periods is on 23rd january, till now i have no period, i m doing pregnency test on 14th march, but it is negative, i also doing ultrasound nothing to be seen, only 2 or 3 small small fibroids on uterous, doctor advise me to take meprate 10mg, for 5days.now i was taking this tablets from yesterday when will my periods will start. and is that any other problem, please tell me.