So you have run a two tailed t-test. You are hoping that the absolute value of the t-statistic has a probability of being observed less than 1 in 20 (0.05) if the null hypothesis is true. In this case we are all happy to reject the null hypothesis and write the manuscript.
The outcome was not as expected, though there were no problems with replication or the experimental design. The probability of observing a difference as large or larger was greater than 0.95 in this experiment.
Are you comfortable concluding that the results support the null hypothesis?