Delayed Periods and Possible Pregnancy.

My last period started on 27 August. I usually get my period every month, but I don't know my exact cycle length. On 23 September, I had genital contact with a male partner. There was an attempt at vaginal entry, but as far as I know, the penis did not actually enter the vagina. There was no ejaculation inside the vagina. My period has not started yet(7 OCT), and took a urine test on 6 OCT and it was negative .  I also consulted another doctor and was prescribed Norate-10 CR (norethisterone acetate 10 mg) and Zefic-Plus (ferrous ascorbate + folic acid). I think she misunderstood as she only asked the date of my last periods and not the date of my first sexual contact and gave me medicines that could bring my periods . There was just a urine test which was negative as it was just 13 days after the contact .I want to confirm with you whether I should take these medicines and whether they are appropriate if I am pregnant and please also tell which medicines I should take.