Implantation Bleeding?

I hadn't had a period for three months (exactly the same as last year) and started up in lateNovember. The period was very light this time. I took an ovulation test during projected ovulation and I was on schedule again. I then had tender and itchy breasts, nausea and back aches. I then started bleeding two weeks after my last period and it lasted two days and was very heavy and lasted four days   Is it possible it's implantation bleeding?