By using the Approximate Solar Coordinates formulas on the U.S. Naval Observatory website, you can calculate the ecliptic longitude of the Sun (L) and the distance between the Earth and Sun (R) for any date. Then, The distance travelled between two dates is approximately s=R*(180/pi)*(L2-L1), where R is the average distance during the interval, and L2 and L1 are the ecliptic longitudes. Since the Earth's orbit is almost circular, this approach is reasonably accurate even when performing the calculation over an entire month. These are the results that I get, where the distance s is in Astronomical Units (AU, the average distance between the Earth and Sun).
Month Distance Travelled, days ave. daily ave. change accl.
Jan 2019 0.542 AU 31 .00175 AU 0 miles 0 f/ss
Feb 0.488 28 .00174 AU - 475 miles 0.000672
Mar 0.536 31 .00173 AU - 1300 miles 0.001840
Apr 0.514 30 .00171 AU - 1490 miles 0.002104
May 0.527 31 .00170 AU - 1210 miles 0.001709
Jun 0.508 30 .00169 AU - 651 miles 0.000921
Jul 0.525 31 .00169 AU 0 miles 0
Aug 0.526 31 .00170 AU 279 miles 0.000395
Sep 0.513 30 .00171 AU 1300 miles 0.001840
Oct 0.535 31 .00173 AU 1490 miles 0.002104
Nov 0.522 30 .00174 AU 1300 miles 0.001840
Dec 0.542 31 .00175 AU 744 miles 0.001053
Of course, the variation from month to month is heavily influenced by the number of days in each month, where as the variation from January to July is due to the distance from the Sun.
As a check, I calculated the distance travelled for each day in January 2019 and totaled the distance. That result was s=0.5419 AU compared to s=0.5422 AU when using the calculation for the first and end of the month.