According to our knowledge, the answer is yes. Electric charge is an completely conserved. Therefore, any difference between negative and positive charges has to have its origin at the beginning of our universe. However, even if the universe was charged electrically at the time of inflation, this imbalance could have reduced to unobservable levels.
Another reason for imbalances in charge within the Universe could result from the tiny gap in absolute values between electron and proton charges. However, we have very strong limits in our experiments on the possibility of such a difference. theory offers a number of grounds to believe that they’re fundamentally equivalent.