What Causes Delayed Period After Having Protected Sex?

I have undergone an abortion (DNC) on 20th Jan, after that I had my 2 periods normally, the first on 14th Feb and 2nd on 12 March. On 19th march I had taken Ipill just to avoid any risk as the condem got teared. we immediately used new condom after that. till today I have not got my periods? M i pregnant again