I appreciate your query.
within 72 hours of unprotected intercourse
( as you did in your case ) significantly reduces
your chances of conceiving.
Also, there are high chances of conceiving if the act happened during your ovulatory days ( Day 10 - Day 16 ) of your menstrual cycle.
It is common for the menstrual bleeding pattern to be altered after taking Ipill, as it is hormone containing, which might be the reason for your earlier period.
To be reasonably sure about your pregnancy
status, please go for a Urine ( HCG
) pregnancy test after a couple of weeks .
All the best.