Implantation Bleeding? 6 Day Embryo Transfer

Hi I had 2 embryo transfer one 5 day and one 6 day. On Sat 3/23/19 was day 4 post transfer and I’ve read that is when implantation can occur. I had slight discharge and lower back pain Day 3, Day 4 but need a second opinion on this, the pics are what I wiped . I texted my Dr and said she can not say it’s good or bad that it can happen as part of the process. My Beta is 3/28/19 this Thurs but may use a home test on Wed.