Early period/Irregular bleeding. Doubts,

On 8th June me and my girlfriend had protected sex, for the first time. There was no slippage or breaking of protection. However as we were first timers and had doubts, regarding efficacy of condom, plus risk of pre cum during normal foreplay, we decided to consume an I pill. It was consumed within 12-15hrs on 9th June. There were no major, immediate effects or vomiting occurence. However yesterday on 17th June,(8 days after consuming I pill) , she started experiencing period like bleeding with period like cramps, and it has continued to today on 18th June also. Her normal periods occur between 27th to 30th of the month. Her last period was on 31st May.  What is going on...has the pill been successful ?? We are a bit tensed regarding these.