PA-28 Pilot reported a person was next to the runway during takeoff.

Narrative

It was a great VFR day and I was in a cross-country engine break in flight in a flight school owned aircraft. I landed safely in ZZZ airport from ZZZ1. After a short break to check oil and fuel I decided to depart again towards ZZZ2 by using Runway XX from the Ramp between taxiway X and Y. As usual; I self announce my position and taxi to Runway XX via [Taxiway] Y. I then hold short of Runway XX on Taxiway Y for engine run up. I took my time to do the run up because this is an engine break-in flight by following the run up check list. I was listening on the radio on the CTAF frequency hoping to see if there is any traffic nearby and at the airport at the time. I then self announce on the CTAF frequency to depart Runway XX for a left crosswind departure. Then I noticed someone was walking towards Runway XX from the north side of the field so then I stopped departure and wait for that person to pass. From my vantage point I saw that person was walking parallel along the runway outside the runway environment but it was hard to tell because the incline of the center of the runway was blocking. And my airplane was below the elevated center of the runway. So about 2 mins later I decided to takeoff without seeing any traffic on final. I keyed in the mic to announce my intention to take off Runway XX again and entered the runway environment. By the time I notice that person again it was after rotation speed and I decided it was safer to continue my takeoff. At that time we both have eye contact of each other and she noticed that my aircraft is taking off at that runway and she walked towards taxiway Z. I failed to notice the same person who was still walking on the side of the runway as I entered the runway environment. There was tall grasses on the North side of Runway XX and that may of block my view of the side of the runway. I failed to verify if the runway is clear or not. I was used to spot aircraft and vehicle but not someone walking on the edge of the runway. I also failed to track the movement of that person during my wait. I have forgotten that anything could happen at a non towered airport. I would use extreme caution and double check in the future to prevent this from happening again.