11dpo is still very early to test and get an accurate result. I did not get a BFP with my daughter until 13dpo and with my son at 14dpo.
That hasn't happened to me but I have seen posts where it has happened to other women. Hopefully one of those ladies will share her story with you. I think most women try to wait to test at 14dpo for the most accurate result but I know how hard it is not to test before the TWW is over because I didn't wait either.