unprotected sex after 5 weeks of d&c

I had my d&c on 31st august, bleeded heavily for 3 weeks and it stopped after medicines for 3 days. Yesterday morning, I felt I will have my AF (first period after d&c). There were few blood droplets too. Then, yesterday I had unprotected sex in the evening. While having sex, I found few droplets of blood. At night, I started bleeding not much. I think its not spotting. Because since last night more than half pad is soaked in blood. I am really very confused. Is it just blood or my period had started. Please help. Can I take ipill (emergency contraceptive pill)? Is it safe to have the pill? Or should I wait and observe? Please help