Anxious and fear. To bleed that way?

On 20th September, my partner fingering in my vagina, maybe there is sperm or not I am not sure. And from August , my menstruation cycle was also stop for my irregular period... From 1st October I have started to take Deviry 10 and stop it 5th October. But my period is not started within 12 days and 17th October I also take urine pregnancy test it shows negative. So from 18th October I started to take deviry 10 again and 21st October I have started bleeding while on medicine from that day I also started to take dronis 20 and I have experience bleeding every month.So my queries are: 1. when I started to take deviry 10 first why my period is not started within 12 days , and when I started to take deviry 10 again then my bleeding started is it period or early pregnancy bleeding? 2. I have experience every month bleeding after finishing each pack of dronis 20. During pregnancy is it possible to bleed that way ? basically in Google I saw pregnancy hormones are not enough to stop bleeding.