Uterine lining

Bethania
I am TTC and this month I used fertility injections. Today I'm 9-10 DPO and AF should come on 5/9 or 5/10. Today period cramps and sore boobs also uterine brown lining discharge. I thought this could be implantation but I think it's my period that might start early. What do you all think?  Usually I see this the day that my AF is supposed to start.