Hi, I Am Kerubo. I Had Sex Three Weeks And

Hi,
I am Kerubo. I had sex three weeks and some days after a medical abortion. I was still bleeding when i had sex though without penetration. the following day i bled so haevily with some big clot also coming out. But towards evening the bleeding reduced later in the evening of that day i took postinor2. i also bought norethisteron tablets to stop the bleeding which i began taking that same evening. the following day i wasnt bleeding or it came out in drops. now my question is: will the postinor 2 help prevent any pregnancy? and why did the bleeding suddenly stop/reduce greatly that following day? is it the effect of a pregnacy having occured, the postinor2 or the norethisteron tabs? please answer today. thanx.