Hi, On 4th Day Of My Periods I Had No

Hi, on 4th day of my periods i had no blood n had intercourse with my husband on that night. After that i started bleeding again. Usually on 5th day my bleeding is almost finished but today was my 5th day and m still bleeding. This happened to me for the first time ever. Now i am tensed that when will the bleeding stop and that is there anything serious? The bleeding is not heavy n i have no pains etc. Please help. Thanks