Hiya
Don't rely on implantation bleeding as your indicator of pregnancy, I didn't get implantation bleeding and as I understand, around 50% of women get it.
A home pregnancy test is the only true indicator but all of us here know that we can't wait that long!!!!!! heheheeee....

I truly believe you may get a combination of little indicators that just seem unusual to you. Mine was AF cramps 4-5 days before AF was due. This doesn't normally happen, I normally get AF cramps on the day she arrives. The other little unusual indicator was that I wanted to swallow or spit all the time, it seemed like my saliva glands were in overdrive.
Good luck