A method of determining a formation pressure for a reservoir, the method comprising: receiving measurement data for a pretest of a formation of the reservoir from a data acquisition tool; characterized by: the data acquisition tool being positioned in a wellbore associated with the reservoir; wherein a pretest of the formation of the reservoir is performed by drawing a small volume of fluid from the formation with the data acquisition tool; wherein the measurement data is collected with the data acquisition tool, the pretest including a small pressure drawdown and a resulting pressure buildup; analyzing, with at least one processor of a data processing system, the measurement data to determine a last-read event and a corresponding last-read pressure for the pretest; determining, with the at least one processor, derivative data for a flow regime identification based at least in part on the measurement data; analyzing, with the at least one processor, the derivative data to determine a pressure derivative response; and determining, with the at least one processor, the formation pressure for the formation based at least in part on the last-read event, the last-read pressure, and the pressure derivative response; wherein the step of analyzing the derivative data to determine the pressure derivative response further comprises: analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime, and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime. the data acquisition tool being positioned in a wellbore associated with the reservoir; wherein a pretest of the formation of the reservoir is performed by drawing a small volume of fluid from the formation with the data acquisition tool; wherein the measurement data is collected with the data acquisition tool, the pretest including a small pressure drawdown and a resulting pressure buildup; analyzing, with at least one processor of a data processing system, the measurement data to determine a last-read event and a corresponding last-read pressure for the pretest; determining, with the at least one processor, derivative data for a flow regime identification based at least in part on the measurement data; analyzing, with the at least one processor, the derivative data to determine a pressure derivative response; and determining, with the at least one processor, the formation pressure for the formation based at least in part on the last-read event, the last-read pressure, and the pressure derivative response; wherein the step of analyzing the derivative data to determine the pressure derivative response further comprises: analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime, and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime. analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime, and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime.