I had late period for 4days and the next day I started to bleed.Although my breasts are swollen and I feel like I am pregnant,or is it implantation bleeding.Pls I would like to know,I am curious.

Fafa, it's unlikely that you have Implantation Bleeding. Women will occasionally have irregular periods. It's normal if you have one or two irregular cycles. But if you're sexually active and start having abnormal symptoms, then you should see a doctor.