Tired of wondering :(

My period is supposed to start on the 27th. On the night of 21st, I noticed bright pink on the TP when I wiped. The next morning it was more of a light brown so I assumed it was my period and used a tampon. After all day, there was only a few spots of dark brown on it. Just curious if anyone has experienced similar. Hubby and I have been TTC for 4 years 😓 I know implantation bleeding is not very common so just assuming it’s my period coming/old blood. Just seeing other opinions... I’ve wasted far too much money on tests so I will not be testing until period time :)