Period came one day early and it was too light

Hi,I had sex with my husband on the 9th day after periods nd had ipill within 24 hours..my expected date was on 29th of jan nd my periods came on this month 28th..but my concern is its not like my usual periods days.very less blood nd first day i had a small pain on my lower abdomen..do I go for a pregnancy test or is it normal??pls help..