Norlevo,period,pill, test, withfrawal bleed and fixations....only serious, please...

Hello,
I am having my first love relationship, even if Im 27.I am a fearful person, but my fears have increased in the last2 months.In august the condom slipped off,I took Norlevo even if he hadnt ejaculated;the period came with 2days of anticipation, then I started to take the Loette pill.Currently in the 7day pause I had the withdrawal bleed. But since 2months I have the fixation of being pregnant.I took the test before the bleed(negative).Ijust cant take my thoughts away from it.Im afraid that I wouldnt recognize a pregnancy in time for abortion.My questions:
1.what is the rate of bleeding even in case of a pregnancy?so withdrawal bleed isnt a proof?
2.who guarantees that 7days cannot originate a natural cycle?
3.I realize that this is a great mental problem, how can I feel better?
Thank you!