implantation or period????

Hi girlsssss! so my period is supposed to begin on 12th and we are TTC for 7-8months now... yesterday very soon in morning I started to have creamy discharge heavy and at noon it because very little pink until now but today the creamy because less heavier... I don't have pain just a little backache when I stand up or walk too much... yesterday was weired because I was feeling all day that a bubble is moving in my uterus... not today... what could it mean????? 🙄😐