Hi.My Periods Are Irregular.since Last Few Months,period Starts 8-10 Days

Hi.My periods are irregular.since last few months,period starts 8-10 days earlier.In the last month it was on 11th.so this month I expect it on 5 -6.but as I wanted to post pone periods because I was travelling during the time.hence I took Primolute n tablets for about 6 days starting front 2nd of this month.I stopped it on 8 th.of November.but there are no periods since then.I am also feeling sleepy and nausea.Is it the effects of Tablet?what to do?