Thank you for your query.
Very rarely, it is possible to be pregnant even if you had the bleeding that you assume is your period.
It could be an impending miscarriage
Sometimes, in case of ectopic pregnancy
also, such bleeding occurs.
The other symptoms you describe could be menstrual symptoms or early pregnancy ones.
If this period is not having a normal flow and normal pattern, then take a pregnancy test just to be sure once the bleeding stops.
As you had unprotected intercourse
around the days of ovulation, pregnancy chances do exist.