Is this possible?

So I took a test because I felt sick and thought hey why not it should be negative! The first day of my last period was October 15th to the 20th . I would expect the test to be negative because my levels go down fast . So today I took a first response with second morning urine . The line is there , and pink and came up before the 1 min mark . So my question is could it be that I gotten pregnant a day before my period or the day after my period .