Sore breast still after period is over

I got my period...what I thought was my period the day after it was due...but it was very bright red not really a flow just alot when I wiped..that lasted for 3days didnt really pay attention because I got whooping cough during my period so I have been too sick too notice until the last day I wiped and noticed my bright red blood had alot of mucus and then I remembered its been like that for the last 3 days bright red mucus blood...only when I wipe...im 38 and ive never had that....and then it just suddenly stopped on the 4th day but my breast continued to hurt so thats when I was confused..because my breast always stop hurting the day my period starts....I have a 10yr old and I would like another....has anyones breast continued to hurt 5days after period? Should I take a pregnancy test?