to the original poster:
there are conditions akin to windshear which will cause a plane not to accelerate. Severe enough these are good reasons to abort (we now say: reject) the takeoff.
I can't speak for your exact plane's situation. IT is important to note that we in the cockpit have instruments to help us know how the acceleration is going.
how did YOU know? just seat of the pants? It does sound like a bit of wind shear, but that acceleration was ok and takeoff continued.
Although those planes do slip a little in second gear :-)
I once had a locomotive engineer (train driver) speak to me in the boarding area, he asked how the power got from the engines (in back) to the drive wheels.
I told him we use the shopping cart method. You just push the thing and it rolls. It dawned on him there was no connection to the wheels from the engines. We had a good laugh and remarked that the F7 diesel locomotive looked a great deal like the front end of a 737.
it is important to the original poster that you understand we need AIRSPEED to fly. You can only, at best, feel (sort of)
groundspeed on the runway.
Hey, next time something feels funny, after you land, ask the pilot.