Thank you for query.Pregnancy
depends on timing of ovulation and intercourse.safe period for intercourse is before 9th day and after 21st of menstrual cycle if regular cycles.if you had intercourse in this you are safe and need not bother.stress
(physical and mental)can lead to changes in bleeding pattern.There may be other uterine ovarian hormonal
causes for this.You can do OTC pregnancy test and please consult doctor
for diagnosis and management..