Thanks for the query.
The chances of pregnancy
As you had intercourse in first 10 days of menstrual cycle during which ovulation is unlikely in regular periods and that was protected intercourse
The delay in periods could be because of stress and strain which can alter the hormonal
Other factors like anemia
, poly cystic ovary disease, weight changes etc can also alter hormonal levels and can lead to delayed periods.
So you better once consult gynecologist and get evaluated regarding this.