And I assume
1) You know that there are TWO times in a 4-stroke cycle engine, when the piston is at TDC ..... right? Once on Compression and again on the Exhaust stroke.
2) you know that #1 cylinder is the driver's side front. and
3) to verify means to take that #1 sparkplug out and actually check for cylinder pressure.
If you knew all that, and did it right, then about all that's left is to check your cam-timing; it only takes one backfire for all the old, brittle, nylon teeth to be torn off.