Implantation bleeding?

Alyssa

I woke up with a sore backache (having for the past few days) and my boobs are swollen and have been very sore. I had a backache/cramp that lasted like 3min and had me in tears it was so uncomfortable, a few hours later I’m bleeding. Wanted to see if you guys thought it was implantation or period. I’m supposed to start my period in two days (I’m normally one day late on my apps so possibly three) and I’m 13 DPO.