The general rule is that if you had a regular period then you are not
pregnant. Being pregnant even though you just had your period is a rare
exception, not the rule. You could be pregnant, but it's not likely
that you are pregnant, especially if you have a negative pregnancy
A normal menstrual period comes on time, is the usual amount of flow, and lasts the regular 3-5 days. When you are not pregnant then you get a menstrual bleeding, your period. Your regular menstrual period usually comes about 14 days after ovulation because you are not pregnant.
Being pregnant even though you just had your regular period is a rare exception, not the rule. You could be pregnant, but it's not likely that you are pregnant.
No matter how much you speculate and ask yourself if this was a real period or not, whether it was shorter than usual or came at a different time than usual and whether you could be pregnant or no. The answer is the same:
If you have a negative pregnancy test then you are not pregnant.
Women with regular menstrual periods are unlikely to be pregnant, especially if home pregnancy tests are repeatedly negative. Some pregnant women report that they have vaginal bleeding early on in pregnancy. But this bleeding is usually not like a regular period, it's usually much lighter and irregular, more like spotting. If you are in doubt, do a pregnancy test. It should be positive if you are pregnant.