I Had An Unprotected Sex Last Month After Which I

I had an unprotected sex last month after which I took I pill within 24 hrs. Last month I had periods on 4th but this month I did not have and on 14th there was some bleeding after which had just spots once or twice. I know I pill works but still I thought of taking urine test through prega news and it came out to be positive. Is it possible to b pregnant after having the I pill. And what should I take to abort pregnancy