Pregnancy possibility. Pregnant or not?

It was the 4th day of my periods my boyfriend fingered me after wiping his semen by tissue as I was giving him a handjob. He wiped his penis and fingers with tissue and after 2-3 minutes he fingered me. I was having the period bleeding. My periods continued till next  day's night. After 12 days of the incident I started taking Norethisterone 5mg tablets prescribed by my gynaecologist for painful periods twice a day. I took the medication for 12 days and after completing the medication I got my periods after 3 days. It was a proper bleeding continued till 5 days. I didn't know that I could get pregnant by fingering so I didn't take any precautions. As the periods came after stopping the medication I don't know if it was effect of medication. The periods after completing the pills happened a day before my actual date of periods. Please tell me I can be pregnant or not?