Questions to be asked. 1) I had first time sex (protected) on 19/feb/17 after 5 -6 days of my regular cycle. And now on my next periods it only lasted for one day bleeding. (light.). 3) And after this duration of short period (one day) after 5-6 days I had again sex on 17/March/17 and now again my period lasted only for one day on 7/ April/17 4) Is there any of pregnancy. 5) what are the possible reasons of my one day bleeding. Can first time sex create this irregularity in my periods. Please tell me what to do. For surety how can I check pregnancy. Or tell me. Any symptoms if there is any chances. And also tell me. Any pill or medicine that will terminate my chances (if there any.) and also suitable medication for regularity in periods.